
(xT Jib U * S * DEPARTMENT OF AGRICULTURE, 

BUREAU OF ENTOMOLOGY— BULLETIN NO. 89. 



L. O. HOWARD, Entomologist and Chief of Bureau. 



THE GRAPE ROOT-WORM 



WITH ESPECIAL REFERENCE TO INVESTIGATIONS 

IN THE ERIE GRAPE BELT FROM 

1907 TO 1909. 



-BY 

FRED JOHNSON and A: G. HAMMAR, 

Engaged in Deciduous Fruit Insect Investigations. 

IN COOPERATION WITH THE OFFICE OF THE STATE ZOOLOGIST, 
PENNSYLVANIA DEPARTMENT OF AGRICULTURE. 



Issued October 20, 1910. 




WASHINGTON: 

GOVERNMENT PRINTING OFFICE. 
1910. 




Glass Ail 

Book .0 x7 3 & 



Bui. 89, Bureau of Entomology, U. S. Dept. of Agriculture. 



Plate I. 








The Grape Root-worm (Fidia viticida). 

Fig. 1.— Female beetle ovipositing. Fig. 2.— Beetle on the lower side of a grape leaf. Fig. 3.— Egg 
cluster with average number of eggs. Fig. 4.— Grape eane showing eggs beneath the bark. 
Figs. 5, 6.— Full grown larvae. Fig. 7.— Pupa in cell. Figs. 8, 9.— Lower and upper views of 
pupa. Fig. 10.— Openings in the ground from which beetles emerged. Figs. 3, 5, 6, 8,9, enlarged; 
tigs. 2, 10, about twice enlarged: rig. 7, about three times enlarged; fig. 1, five times enlarged; 
fig. 4, natural size. (Original.) 



k 



U. S. DEPARTMENT OF AGRICULTURE, 

BUREAU OF ENTOMOLOGY— BULLETIN NO. 89. 

L. O. HOWARD, Entomologist and Chief of Bureau. 



THE GRAPE ROOT-WORM 



WITH ESPECIAL REFERENCE TO INVESTIGATIONS 

IN THE ERIE GRAPE BELT FROM 

1907 TO 1909. 




BY 



FRED JOHNSON and A. G. HAMMAR, 

i 

Engaged in Deciduous Fruit Insect Investigations. 

IN COOPERATION WITH THE OFFICE OF THE STATE ZOOLOGIST, 
PENNSYLVANIA DEPARTMENT OF AGRICULTURE. 



Issued October 20, 1910. 




WASHINGTON: 

GOVERNMENT PRINTING OFFICE, 

1910. 



1 



0^ 



& 



s>V 



,ETTER OF TRANSMITTAL. 



U. S. Department of Agriculture, 

Bureau of Entomology, 

Washington, D. C, June 8, 1910. 

Sir : I have the honor to transmit herewith for publication a manu- 
script entitled "The Grape Root- Worm, with Especial Reference to 
Investigations in the Erie Grape Belt from 1907 to 1909," by Fred 
Johnson and A. G. Hammar, agents and experts, of this Bureau. 

The grape root-worm is by far the most serious pest of American 
varieties of grape at the present time and its ravages have caused a 
great depreciation in the value of vineyard properties as well as a 
marked reduction in the yield of fruit. The present report furnishes 
a careful account of the life history and habits of the pest, embodies 
a report on the work undertaken by the Bureau of Entomology in 
the spring of 1907 in the Erie Grape Belt, at the instance of vine- 
yardists, and provided for by Congress, and points out practical 
remedial measures whereby the vineyardists will be able largely to 
avoid future losses. 

During the years 1908 and 1909 the work has been in cooperation 
with the office of the zoologist of the Pennsylvania state department of 
agriculture, as further detailed in the preface. 

I recommend the publication of the accompanying manuscript as 
Bulletin No. 89 of this Bureau. 

Respectfully, R. S. Clifton, 



Acting Chief of Bureau. 



Hon. James Wilson, 

Secretary of Agriculture. 

2 

NOV 4= 1910 
! % 



PREFACE 



The grape root-worm, the subject of the present report, is an 
insect which during the last ten or fifteen years has attracted much 
attention on account of its ravages in vineyards along the southern 
and eastern shores of Lake Erie, comprising in general the grape- 
growing territory of northern Ohio and the Erie and Chautauqua 
grape belts of Pennsylvania and New York, respectively. American 
varieties of grapes, exclusively grown in the above-mentioned regions, 
have heretofore been singularly free' from insects attacking the roots 
of the plant. The Phylloxera, so destructive to the roots of vinifera 
varieties in Europe and in California and elsewhere in the United 
States where these are grown, fortunately does not seriously injure 
varieties of American grapes. The grape root-worm, however, has 
come to be recognized as the most serious of the two hundred or 
more species of insects in the United States which feed directly or 
indirectly upon our native grapes. 

The destructiveness of the insect in the Erie grape belt in the 
general neighborhood of North East, Pa., led, through the represen- 
tations of prominent vineyardists, to a provision by Congress for an 
especial investigation of the pest by the Bureau of Entomology. 
This work was begun in the spring of 1907, and a laboratory was 
established at North East, Pa., which place has been continued as 
headquarters during the years 1908 and 1909. During the latter 
two years, by contract entered into between the Hon. James Wilson, 
Secretary of the United States Department of Agriculture, and the 
Hon. N. B. Critchfield, secretary of agriculture of the State of Penn- 
sylvania, the investigation has been in cooperation with the office 
of the state zoologist of the Pennsylvania department of agricul- 
ture. The work has covered a wide range of investigations, in- 
cluding a thorough inquiry into the life history and habits of the 
insect, large-scale experiments, with remedial measures, and the 
demonstration of the effectiveness of measures known to be of 
value, including the renovation and improvement of young and old 
vineyards already seriously injured. 

Mr. Fred Johnson has been in immediate charge of the field work 
during the entire period of the investigation, and was assisted in 
1907 by Messrs. W. B. Wilson and P. R. Jones, the former engaged in 
field work and the latter in life-history studies. During the years 

3 



4 THE GRAPE ROOT-WORM. 

1908 and 1909 Mr. A. G. Hammar was detailed to the grape root- 
worm investigation and devoted his attention particularly to life- 
history studies, assisted by Mr. E. Selkregg. Prof. H. A. Sur- 
face, state zoologist of Pennsylvania, assigned, as a representative 
of the Pennsylvania department of agriculture, Mr. F. Z. Hartzell 
during 1908, and Mr. H. B. Weiss during the year 1909. These 
gentlemen assisted in field operations and rendered most efficient 
service, contributing much to the success of the investigation. In 
the present report Mr. Johnson has prepared the manuscript detail- 
ing results of field experiments and Mr. Hammar the manuscript 
detailing results of life-history studies, and most of the illustrations. 

The results obtained by this study, as detailed in the subsequent 
pages, will, it is believed, furnish entirely practicable and economical 
measures for the control by vineyardists of this serious insect pest. 
It is essential, however, in order that satisfactory results may be 
secured, that the recommendations given be followed in a thorough 
and timely manner. 

The authors desire to express their thanks to the following vine- 
yardists of North East, Pa. : Mr. George Blaine, Mr. W. S. Wheeler, 
Mr. R. Davidson, Mr. W. E. Gray, Mr. H. S. Mosher, and Mr. A. I. 
Loop, for their direct assistance in the conduct of this investigation 
by placing large blocks of their vineyards at the disposal of the 
Bureau of Entomology for several seasons and assisting in conduct- 
ing experiments thereon. They also wish to thank the large number 
of vineyardists whose interest in the work during its progress has 
been a source of inspiration and gratification to them throughout 
this period. 

A. L. QUAINTANCE, 

In Charge of Deciduous Fruit Insect Investigations. 



CONTENTS 



Tage. 

Introduction 9 

History 10 

Origin and distribution 12 

Food plants 13 

Character of injury and destructiveness 14 

Beetles related to the grape root-worm beetle 15 

Beetles frequently mistaken for the grape root- worm beetle 16 

Description 19 

The egg 19 

The larva 19 

The pupa 20 

The adult or beetle 21 

Seasonal history 22 

The adult or beetle 22 

The process and time of emergence 22 

Variation in the time of emergence 25 

Feeding before and after egg deposition 25 

Mating and its bearing upon egg deposition 28 

Process of egg deposition 28 

Variation in the number of eggs per cluster 29 

Number of separate ovipositions by individual females 29 

Number of eggs deposited by individual female beetles 30 

The oviposition period for the season of 1909 31 

Longevity of male and female beetles 32 

The egg 33 

Incubation period of the egg 33 

The larva 35 

Vitality of the newly hatched larva 35 

Feeding and development of the larva before wintering 35 

Wintering of the larva in an earthen cell 36 

Spring feeding of the larva 37 

Time and making of the pupal cell 37 

The post-larval stage 38 

The pupa 39 

The process of pupation 39 

Position of the pupa in the cell 39 

Time of pupation in the field and in breeding cages 39 

Duration of the pupal period 40 

Life cycle of the grape root-worm as determined by rearing 40 

Seasonal variations in the life history of the grape root- worm 41 

Rearing and experimental methods 44 

Summary of life-history studies of the grape root- worm 50 

5 



b THE GRAPE ROOT-WORM. 

Page. 

Natural enemies 50 

Predaceous insects -. 50 

Parasitic insects 51 

Life history of Fidiobia flavipes Ashm 52 

A dipterous parasite 55 

Double parasitism 50 

Vineyard conditions in the Lake Erie Valley 57 

Remedial measures for the control of the grape root- worm 59 

Evolution of preventive measures 59 

Cultural methods for the destruction of pupa? 61 

Effect of poison sprays on the beetle in the field 63 

Cage experiments with poison sprays against the beetles 64 

Field experiments with poison sprays against the beetles 66 

Comparative effectiveness of arsenate of lead and arsenite of lime 68 

Results of vineyard experiments with poison sprays 70 

Results of vineyard renovation experiments 75 

Renovation experiment on an old vineyard 75 

Methods of obtaining and recording results 78 

Renovation experiment on a young vineyard 80 

Sprays 83 

Arsenical poisons 83 

Combining insecticides with fungicides 84 

Preparation of Bordeaux mixture 84 

Plants for preparation of the spray mixture 85 

Time of application of sprays 86 

Number of spray applications 86 

Pressure to be maintained in spray applications 88 

Spraying apparatus 88 

Horse-power sprayers 88 

Gasoline-engine sprayers 88 

Compressed-air outfits ?- 88 

Carbonic-acid-gas sprayers 89 

Hand pumps 89 

The care of spraying apparatus 89 

Nozzle adjustment 89 

Nozzles 89 

Recommendations 89 

Destruction of the adults or beetles 89 

Destruction of the pupae 90 

General treatment of infested vineyards 91 

Bibliography '. 93 

Index 98 



ILLUSTRATIONS 



PLATES. 

Page. 

Plate I. The grape root- worm (Fidia viticida). Fig. 1. — Female beetle oviposit- 
ing. Fig. 2. — Beetle on the lower side of a grape leaf. Fig. 3. — 
Egg-cluster with average number of eggs. Fig. 4. — Grape cane, 
showing eggs beneath the bark. Figs. 5, 6.— Full-grown larvae. 
Fig. 7. — Pupa in cell. Figs. 8, 9. — Lower and upper views of pupa. 
Fig. 10. — Openings in the ground from which beetles emerged. 

Frontispiece. 

II. Feeding marks on grape leaves, made by the beetle of the grape root- 
worm. Fig. 1. — Appearance of fresh feeding marks. Fig. 2.- — 
Feeding marks which have become enlarged with the growth of the 
leaf 14 

III. Feeding marks on the larger roots and underground part of the stem 

of a grapevine by larva? of the grape root-worm, resulting in the 
death of the plant 14 

IV. Destruction of root fibers by larvae. Fig. 1. — Five-year-old grapevine 

with normally developed root-system; enlarged portion showing 
root fibers. Fig. 2. — Four-year-old grapevine, showing result of 

feeding by larva? of the grape root- worm 16 

V. Ridge of soil under trellis. Fig. 1. — Vineyard view in the spring, 
showing ridge of undisturbed soil under the trellis. Fig. 2. — Vine- 
yard view, showing ridge of soil under trellis as formed at the last 
cultivation of the preceding summer. North East, Pa 62 

VI. General view of Mr. Roscoe Davidson's vineyard at North East, Pa., 
where spraying experiments against the grape root-worm were con- 
ducted during 1907, 1908, and 1909 70 

VII. Views of experimental plats in Mr. Roscoe Davidson's vineyard at 
North East, Pa. Fig. 1. — Retarded growth of vines in the un- 
sprayed plat. Fig. 2. — Vigorous growth of vines in the sprayed 

plat 74 

VIII. Views of the Porter experimental vineyard, showing comparative 
growth of the vines in 1907 at the beginning of the experiment 
(upper figure), and in 1909 at the end of the experiment (lower 
figure). North East, Pa 80 

IX. Condition of fruit on vines in plats of the Porter experimental 
vineyard. Fig. 1. — Average condition of berries in the untreated 
plat. Fig. 2. — Average condition of berries in the treated plats. 

North East, Pa., 1909 . 80 

X. Spraying outfits for vineyards, in use at North East, Pa. Fig. 1. — 
Spray-mixing plant. Fig. 2. — Gasoline-engine sprayer in opera- 
tion. Fig. 3. — Compressed-air sprayer. Figs. 4, 5. — Horsepower 
or geared sprayers 86 

TEXT FIGURES. 

Fig. 1. Map showing distribution of the grape root-worm (Fidia viticida) 12 

2. The California grape root- worm (Adoxus obscurus) : Adult or beetle 15 

3. The grapevine Fidia (Fidia longipes) : Adult or beetle 16 

7 



8 THE GEAPE EOOT-WORM. 

Page. 

Fig. 4. The grapevine flea-beetle (Halticachalybea): Adult 16 

5. The rose-chafer ( Macrodactylus subspinosus): Adult or beetle 17 

6. The redheaded Systena (Systena frontalis): Adult or beetle 18 

7. The grapevine Colaspis (Colaspis brunnea): Adult or beetle 18 

8. The grape root-worm (Fidia viticida) : Larva and details 19 

9. The grape root- worm : Pupa and details 19 

10. The grape root-worm: Adult or beetle 20 

11 . The grape root- worm : Structural parts of beetle 21 

12. Diagram showing time and development of a single individual of the 

grape root-worm under average conditions, as observed in 1909, at 
North East, Pa 23 

13. Curve showing time and relative emergence of beetles of the grape root- 

worm from the ground in rearing cages at North East, Pa., 1909 24 

14. Curves showing variations in time of emergence of beetles of the grape 

root- worm from different kinds of soil. From rearing experiments 
during 1909 at North East, Pa 25 

15. Curve showing time of egg deposition and relative abundance of eggs 

laid in rearing cages by beetles of the grape root- worm at North East, 

Pa. , during 1909 32 

16. Diagram showing variation in time of emergence of beetles of the grape 

root-worm during 1907, 1908, and 1909, at North East, Pa 42 

17. Temperature curves showing the daily records of the maximum and 

minimum temperature during the breeding period of 1909 at North 
East, Pa 43 

18. Portion of the outdoor rearing shelter used in the rearing of insects at 

North East, Pa., during 1909 45 

19. Wooden-frame box with glass bottom and wire-screen cover used in 

studying the pupal stage of the grape root- worm beetle 45 

20. Earthen pot with glass cyclinder used in rearing the grape root- worm. . 46 

21. Rearing cage with glass sides used in the study of the larva of the 

grape root- worm beetle 47 

22. Earthen pot with wire-screen cover used in rearing the grape root- 

worm 48 

23. Diagram illustrating seasonal history of the grape root-worm as observed 

during 1909 at North East, Pa 49 

24. Fidiobiaflavipes, an egg-parasite of the grape root- worm: Adult and 

enlarged antenna 52 

25. Diagram showing the relation between the three generations of the 

Fidiobia parasite and the relative occurrence of eggs of the grape 
root-worm at North East, Pa., during 1909 55 

26. Larva of an undetermined insect parasite of the eggs of the grape root- 

worm 56 

27. Lathromeris fidise, an egg-parasite of the grape root- worm: Antenna and 

forewing 57 

28. Horse hoe used in removing the soil from beneath the trellis in vine- 

yards 61 

29. Young grapevine, unsprayed, showing extensive feeding by beetles of 

the grape root-worm. North East, Pa. , 1909 66 

30. Young grapevine sprayed with arsenate of lead against the beetles of the 

grape root-worm. North East, Pa., 1909 87 

31. A large nozzle of the cyclone type 89 



THE GRAPE ROOT-WORM 

WITH ESPECIAL REFERENCE TO INVESTIGATIONS 
IN THE ERIE GRAPE BELT FROM 1907 TO 1909. 



INTRODUCTION. 

During the past decade the insect Fidia viticida Walsh (PI. I), 
a chrysomelid beetle known to the vineyardists of the Lake Erie 
Valley as the "grape root-worm" beetle, which in the larval stage 
feeds upon the roots of the grapevine, has become by far the most 
destructive insect pest attacking the grape in that region. 

The following pages present the extent and findings of an investi- 
gation conducted at North East, Pa., during the seasons of 1907, 
1908, and 1909. These investigations were undertaken in order to 
make a thorough study of the life history and habits of this insect, 
to conduct experiments with a view to its control, and to make field 
experiments to demonstrate the practical commercial value of those 
methods giving greatest promise of effective results. 

Since the grape root-worm is a grape pest of long standing, a brief 
resume of its history is given, both from the standpoint of entomolog- 
ical classification and from that of the development of remedial 
measures for its control. 

Its origin, distribution, and food plants are considered, brief de- 
scriptions of allied beetles and of those beetles found upon grape- 
vines likely to be mistaken for the grape root-worm are given, 
and also a description of the character of the injury to the" vine 
wrought by the insect and the extent of its destructiveness. 

The technical descriptions of the different ages of the insect are 
followed by a presentation of life-history studies involving many 
careful experiments with numerous individuals. These studies were 
undertaken to determine the length of the stages and the time at 
which the different changes occur. This work was conducted for 
three consecutive years with a view to determine the effect, in the 
development of the insect, of seasonal variations due to varying 
climatic conditions, and it has been productive of very interesting 
results which have an important bearing on the time of application 
of remedies. Soil conditions and altitude of vineyards are also con- 
sidered in this same relation. 

9 



10 THE GEAPE ROOT-WORM. 

Preceding the discussion of remedial measures a brief summary is 
given of the conditions in vineyards in the Lake Erie Valley since 
their invasion by the grape root-worm, dealing with the age and con- 
dition of vines at the time of its advent, the increase in area of new 
vineyards, the insect's comparative destructiveness to old and newly 
planted vines, and the relative responsibility of the pest for the 
fluctuations of crop yields during the past decade. 

Cultural methods are considered with special reference to the 
destruction of pupa? in the soil. 

In the presentation of the data dealing with poison sprays for the 
destruction of the beetles, details of experiments are given, first, to 
show the efficiency of arsenicals as a direct killing agent of the beetles 
in confinement and also in the open field ; second, to show the rela- 
tive value of arsenate of lead and of arsenite of lime; and, third, 
to show the cumulative value of poison-spray applications on large 
vineyard areas, both in crop yield and in vigor of vines as a result 
of three consecutive years of this treatment. 

Following this experimental data on poison sprays the details are 
given of field demonstration experiments with two run-down vine- 
yards, conducted for three consecutive seasons. One, an old vine- 
yard of about 10 acres, the other a young vineyard of about 5 acres. 
The condition of each of these vineyards at the time the experiment 
was undertaken is described and the plan of treatment — covering 
general vineyard practice, such as pruning back of badly injured 
vines, fertilizing, cultivation, and spraying with arsenicals — is given, 
accompanied by the collected data showing the results of this treat- 
ment in lessening deposition of eggs by the grape root-worm beetles, 
in the diminution of grape root-worm larvae in the soil about the 
roots of the vine, in the increase in crop yield, and in the general 
effect of this combined treatment upon the health and vigor of the 
vines. 

The remaining pages contain a brief discussion of arsenicals as 
stomach poisons against the grape root-worm beetles, the desirability 
of combining them with a fungicide when spraying for this pest, 
spraying methods and spraying machinery as related to vineyard 
treatment, and recommendations as to time and manner of making 
applications. 

HISTORY. 

The first record of the beetle, Fidia viticida, the adult of the grape 
root-worm, as a pest of economic importance upon grapevines was 
made by B. D. Walsh in 1866 in the Practical Entomologist (see 
Bibliography), and it is also to him that we are indebted for the first 
description of this species of the genus Fidia. Yet as far back as 
1826 this insect appears in entomological literature under a variety 



HISTORY. 11 

of names. The first reference we find to this species is in M. J. 
Sturm's Catalog Insecten Sammlung, at that date (1826) under the 
name of Colas pis jlavescens. Under a later catalogue (1843) by the 
same author it is listed under the name of Fidia lurida Dej. Dejean, 
in his Catalogue des Coleopteres (1837), names two species, Fidia 
lurida Dej . and Fidia murina Dej . 

The genus Fidia was first characterized by Baly in 1863, who used 
the name Fidia suggested earlier by Dejean. Crotch, however, in 
1873, described this insect under the name of F. murina and Lefevre, 
in 1885, described it under F. lurida. In 1892, when Dr. George H. 
Horn revised the Eumolpini of Boreal America, F. murina and F. 
lurida were found to be synonyms of Fidia viticida as described by 
Walsh in 1867.° 

Since 1866, when this insect was first reported as occurring in 
destructive numbers in Kentucky, it has developed into the most 
serious insect infesting vineyards east of the Rocky Mountains. At 
that date only the adult form and its injury to the vine by feeding 
upon the foliage was known. Walsh assumed that the larval habits 
of the pest were similar to those of the grape flea-beetle (Haltica cha- 
lybea 111.), and that it would be found the most destructive in this 
stage feeding upon the foliage. In the former assumption he was 
correct, for it is the injury of the larval form which is inimical to 
infested vines, not upon the leaves, however, as Walsh supposed, but 
upon the roots, as shown by later investigations. The year following, 
the insect was reported from St. Louis and Bluffton, Mo., and in 
1868 Prof. C. V. Riley, in his first report on injurious and beneficial 
insects of Missouri, mentions it as "the worst foe to the grapevine 
in Missouri." In 1870 specimens were received by Riley from Bun- 
ker Hill, 111., and in 1872 Mr. S. H. Kridelbaugh reported it present 
in Iowa in injurious numbers. 

It was not until 1893, however, that some light was thrown upon 
the earlier stages of the pest. In December of that year Prof. F. M. 
Webster, then entomologist of the Ohio Agricultural Experiment 
Station, received larvae from the vicinity of Cleveland, Ohio, where 
they were said to occur in great numbers about the roots of vines. 
Later there developed from these larva? the complete form which 
proved to be the beetle Fidia viticida, hitherto the only stage of the 

a The validity of the technical name of the grape root-worm (Fidia viticida Walsh) 
might be questioned. The names lurida and murina were used previous to viticida, 
but as nomina nuda; the specific description was first given in 1867, when Walsh described 
the insect under the name Fidia viticida. Baly in 1863 characterized the genus and 
designated lurida as the type of the genus, though the species under that name had 
not yet been described. The specific name viticida Walsh has the priority, since 
the valid name murina was first used in 1873 by Crotch, and lurida in 1885 by Lefevre, 
both writers using the early manuscript name of Dejean. 



12 



THE GRAPE ROOT-WORM. 



insect known to entomologists. During the season of 1894 Professor 
Webster made a detailed and accurate study of the life history of the 
insect, described its immature stages, and made numerous field 
experiments to determine effective methods of control, which are 
referred to in another part of this bulletin. 

In 1896 Prof. J. T. Stimson recorded injury caused by this insect 
in Arkansas. Dr. John B. Smith, in his Catalogue of Insects of 
New Jersey, 1900, reports its occurrence throughout that Sfcate. 
Dr. L. O. Howard reported it from Bloomington, 111., in 1901. In 
later years the insect appeared as a pest in the grape region of Penn- 
sylvania and New York, where from 1900 to 1906 it was the subject 
of detailed studies, treating both of its life history and remedial 
measures, by the late Prof. M. V. Slingerland, of Cornell University, 




Fig. 1. — Map showing distribution of the gmpe root-worm (Fidia viticida). (Original.) 

and by Dr. E. P. Felt, state entomologist of New York. The reports 
of the investigations by the former are embodied in the bulletins of 
the entomological division of Cornell University, and the publica- 
tions of the New York State Museum contain reports of those 
made by the latter; all publications of these two investigations are 
listed in the bibliography accompanying this bulletin. 

ORIGIN AND DISTRIBUTION. 

The grape root-worm has at present been recorded only from 
North America, and it is without doubt a native species, feeding 
originally on wild grapevines, as it still does to some extent. 

The insect is widely distributed in the Mississippi Valley and in 
the Eastern States. The map (fig. 1) shows the distribution as 
recorded at present. 



FOOD PLANTS. 13 

In literature the insect is reported from the following States: 
Arkansas (Riley, Howard, and Stimson) ; Illinois (Walsh and Riley) ; 
Iowa (Kridelbaugh) ; Kansas (Webster) ; Kentucky (Walsh) ; Mis- 
souri (Riley); New Jersey (Smith); New York (Lintner, Slingerland, 
and Felt); Ohio (Webster); Pennsylvania (Slingerland and Felt). 

According to records of the Bureau of Entomology the insect 
occurs in Illinois, Kentucky, Michigan, Mississippi, Missouri, New 
York, North Carolina, Ohio, Pennsylvania, Texas, Virginia, and 
West Virginia. 

In the collections of the National Museum are specimens from the 
following States: District of Columbia, Illinois, Kansas, Maryland, 
Missouri, Nebraska, New York, North Carolina, Ohio, Pennsyl- 
vania, Texas, and Virginia. 

From the following localities it has not yet been recorded, but 
probably does occur as these are neighboring sections of infested 
places: Southern parts of Indian Territory, Tennessee, and Wiscon- 
sin; northern parts of Alabama, Georgia, Louisiana, and South 
Carolina. 

FOOD PLANTS. 

From early records of this insect it is evident that the beetle of 
the grape root-worm was observed feeding upon wild grapes long 
before it was known to infest cultivated varieties. Riley reported 
the beetle feeding upon the leaves of wild grapes and upon the red- 
bud (Cercis canadensis). Several writers have found it feeding 
upon the foliage of the Virginia creeper (Ampelopsis quinquefolia) . 
With the extensive cultivation of improved varieties of native 
species of grapes, the insect has found in these a more available food 
plant. The larval form and its underground habits became first 
known through its abundance and destructiveness in vineyards. 

On the wild grapevine the grape root-worm does not breed in 
extensive numbers, because the conditions in woodlands are less 
favorable than those existing in vineyards. The chances for the 
newly hatched larvae to reach the roots of the wild grapevine are 
greatly limited, since the plants spread their aerial growth exten- 
sively and in such a manner that the parts of the vine above ground 
are not directly above the root system. Under such conditions 
numbers of the larvae on dropping to the ground do not reach the 
needed food plant and probably perish. A single female beetle, 
however, lays a considerable number of eggs, and out of the many 
hatching larvae the chances are that always several will survive to 
perpetuate the species. 

In the course of this investigation at North East, Pa., several 
attempts were made to locate the larvae on roots of wild grapevines, 
but in no instance were larvae found or any signs of feeding observed on 



14 THE GKAPE ROOT-WORM. 

the roots. In the breeding work, however, larvae were reared on 
wild grapevines, which shows that it is possible for the larvae to 
exist on these plants. In 1909 larvae hatching July 26 were placed 
in large earthen pots (fig. 22) in which, some time previously, wild 
grapevines had been planted. On examining the cages in the fall 
of the same year (1909) a number of larvae were found to have 
attained their normal growth, as compared with other larvae reared 
under similar conditions on cultivated vines. 

CHARACTER OF INJURY AND DESTRUCTIVENESS. 

The injury wrought by this pest on the grapevine occurs both 
above and below the surface of the ground ; however, by far the greater 
damage results from its work upon the roots. The injury above the 
ground is done by the beetles; that upon the roots by the grubs or 
larvae. 

The first intimation that the observant vineyardist is likely to 
obtain of the presence of this pest upon his vines is the appearance, 
late in June or early in July, of chainlike markings upon the upper 
surface of the foliage (PL II). These markings are made by the 
beetle. Ordinarily this scoring of the leaves is not sufficient to 
materially affect the health of full-grown thrifty vines. Where the 
beetles are very numerous, however, and the foliage sparse, it not 
infrequently happens that the leaves are so badly scored that in a 
short time they take on a brown appearance and hang about in 
shreds. In the case of newly planted vines (fig. 29) extensive 
feeding by the beetles greatly retards the growth of the young plant 
and proves a great obstacle in the starting of a new vineyard. On 
the thick-leaved varieties of grapes, such as the Concord, Worden, 
and Niagara, this feeding does not extend through the heavy pubes- 
cence on the lower surface. The pubescence holds together only a 
short time, however, and soon either dries out or is torn apart by 
the growth of the leaf. On the thin-leaved varieties, as the Dela- 
ware, and on the wild species of grape, holes are eaten entirely 
through the leaf, usually assuming the characteristic chainlike irregu- 
larity of form. 

It is, however, to the. larvae of this pest feeding upon the roots of 
the vines that the direct cause of the injury and death of so many 
vines is due. The work of the larvae upon the roots may be recog- 
nized, when the vines are removed from the soil, by the absence of 
root fibers, by channels along the larger roots, and by pittings on 
the main trunk. (See PL III.) Vines that have become well 
established before the infestation by larvae will sometimes withstand 
the attack of a considerable number of grubs, especially if the soil 
is rich and has been well tilled. The evidence of continued heavy 
infestation is indicated by absence of fibers upon the whiplike roots 



Bui. 89, Bureau of Entomology, U. S. Dept. of Agriculture. 



Plate II. 




Feeding Marks on Grape Leaves, Made by the Beetle of the Grape Root-worm. 

Fig. 1.— Appearance of fresh feeding marks. Fig. 2.— Feeding marks which have become en- 
larged with the growth of the leaf. Natural size. (Original.) 



Bui. 89, Bureau of Entomology, U, S. Dept of Agriculture. 



Plate III. 




Feeding Marks on the Larger Roots and Underground Part of the Stem of a 
Grapevine by Larv/e of the Grape Root-worm, Resulting in the Death of the 
Plant. Lower Figure Natural Size. (Original.) 



BEETLES RELATED TO GRAPE ROOT-WORM BEETLES. 



15 



(PL IV, fig. 2, in comparison with fig. 1) extending from the main 
root a distance of several feet. The extremities of such roots are 
frequently dead and in a decaying condition, and the portion near 
the stem is much channeled and pitted by the feeding of the larger 
larvae (PI. III). The life of such vines during this infestation has 
been sustained by the throwing out of new fibrous roots either at 
the crown or from the large lateral roots at a short distance from the 
base of the vine. If the number of larvae increases sufficiently to 
eat off these new fibers, the whole vine declines quite rapidly, and the 
effect of the attack is readily recognized by a sickly stunted growth 
of vine and undersized clusters of fruit, and in extreme cases by the 
early shedding of foliage and actual shriveling of fruit before the 
ripening period. 

BEETLES RELATED TO THE GRAPE ROOT-WORM BEETLE. 

The grape root-worm is a member of the large group of leaf-eating 
beetles known as the Chrysomelidse. To this family belong the 
common Colorado potato beetle 
(Leptinotarsa decemlineata Say), 
the elm leaf -beetle (Galerucella lu- 
teola Mull.), the asparagus beetle 
(Crioceris asparagi L.), several 
important pests of the genus 
Diabrotica, the grapevine flea- 
beetle (Haltica chalybea 111.), and 
many other injurious beetles. 

Closely related to Fidia viti- 
cida Walsh (fig. 10) is the Cali- 
fornia grape root-worm (Adoxus 
obscurus L.) (fig. 2), of which 
there are two varieties, namely, 
a black form, known as A. obscu- 
rus, and a bicolored form, known 
as A. obscurus vitis. Both vari- 
eties occur in this country and 
have been reported from sev- 
eral widely separated States and 
from Canada. It is found generally in Europe and throughout 
Siberia. At present it is becoming injurious to vineyards in Cali- 
fornia, infesting the European varieties of the cultivated grape. A 
valuable contribution to the knowledge of this insect was published 
by Mr. II. J. Quayle a in 1908. In habits this beetle is in most 
respects similar to the eastern grape root-worm, Fidia viticida, and 
the two pests can thus be combated with similar methods. It will, 
however, be necessary to take into consideration the local conditions 




Fig. 2. — The California grape root-worm {Adoxus 
obscurus): Adult or beetle. Much enlarged. 
(Original.) 



"Bul. 195, Cal. Agr. Exp. Sta., 1908. 



16 



THE GRAPE ROOT-WORM. 




and variations as to the habits of the beetles in order to accomplish 

effective results. 

There are at present 6 species of the genus Fidia known to Boreal 

America and by including 
those occurring in Central 
America there are 14 known 
species. Of these, Fidia viti- 
cida Walsh and Fidia lon- 
gipes Melsh. have been re- 
corded as being injurious to 
the native varieties of the 
domesticated grape. Fidia 
longvpes (fig. 3) is found gen- 
erally throughout the Mis- 
sissippi Valley and in the 
Eastern States. It is, how- 
ever, less common than F. 
viticida. In Missouri and 
Kentucky it occurred in in- 
jurious numbers on the Con- 
cord and on Norton's Vir- 
ginia varieties of grapes. 
The earlier stages of this 
beetle are not yet known. 
For characteristic distinction of the species of Fidia reference is 

made to the works of Lefevre, Jacoby, Horn, and Schseffer, as listed 

in the appended bibliography 

(p. 93). 

BEETLES FREQUENTLY MIS- 
TAKEN FOR THE GRAPE 
ROOT-WORM BEETLE. 

There are several different 
kinds of beetles injurious to the 
grapevine, and these when found 
in numbers are frequently mis- 
taken for the grape root-worm 
beetles. It is essential that an 
insect pest should be properly 
determined before any success- 
ful control measure can be prop- 
erly recommended. Although 
most leaf-eating beetles can 
be controlled with a poison spray, as used against the grape root- 
worm, there exists a marked difference in the time of appearance of 



Fig. 3. — The grapevine Fidia (Fidia longipes): Adult or 
beetle. Much enlarged. (Original.) 




Fig. 4.— The grapevine flea-beetle (Haltica chaly- 
bea): Adult. Much enlarged. (Original.) 



Bui. 89, Bureau of Entomology, U. S. Dept. of Agriculture. 



Plate IV. 




Fig. 1.— Five-year-old grapevine with normally developed root-system; enlarged portion showing 

root fibers. (Original.) 









Z^r'~ ' 














\ is 












>\ 


-i 


















/• f*^m t ' 






^Nfete 






/ J^' 




^r^T 


•^^^^ 




^s^v 


^r 




/Sp^^ 


--7" 


I J\ 


V 1 . '^»*^ 






^ 





Fig. 2.— Four-year-old grapevine, showing result of feeding by larvae of the grape root-worm. 

(Original.) 



Destruction of Root Fibers by Larv/e. 



BEETLES MISTAKEN FOR GEAPE ROOT-WORM BEETLES. 



17 



the different pests, so that an application intended for one may not 
at all affect another. The descriptions with figures of the following 
beetles and of their more characteristic habits will aid the vineyardist 
in distinguishing the grape root-worm from other injurious species. 

The grapevine flea-beetle (Haltica chalybea 111.) (fig. 4), measuring 
about one-fifth of an inch in length, is readily recognized by its brilliant 
metallic color, which varies from steel blue to green. It is of a robust 
shape, with thickened thighs well adapted for jumping. With the 
opening of the buds of the grapevine in the spring the beetle generally 
makes its appearance. The larvae, which are found in the early part 
of the summer, feed, 
like the adult, upon the 
leaves of the grape. 

The rose-chafer 
( Macrodactylus subspi- 
nosus Fab.) (fig. 5) ap- 
pears as a rule at the 
time of the blossom of 
the grape. It is a slen- 
der beetle about one- 
third of an inch long, 
with the bod}^ tapering 
a little toward each ex- 
tremity. It is covered 
with a grayish-yellow 
down, which gives rise 
to its color. The pale 
reddish legs are long, 
at the joint armed with 
prominent spines, and 
terminate in very long 
black claws. The an- 
tennae, or "feelers," are 
short and have at the 
end a laminated club- 
like structure. The beetle readily attracts attention because of its 
activity and great abundance wherever present. It preferably feeds 
upon the clusters of the blossom, and to some extent upon young 
grape-berries and leaves. . 

The red-headed Systena (Systena frontalis Fab.) (fig. 6) somewhat 
resembles the previously described beetle. It is, however, smaller, 
measuring about one-sixth of an inch in length, and is black in color 
except for a pale reddish area between the eyes. This beetle has of 
late become quite injurious to young grapevines, feeding upon the 
leaves to such an extent that it often kills the vines. The feeding 
51282°— Bull. 89—10 2 




Fig. 5.— The rose-chafer {Macrodactylus subspinosus); Adiilt or 
beetle. Much enlarged. (Original.) 



18 



THE GRAPE ROOT-WORM. 



marks of the beetles are quite characteristic, consisting of round 
patches eaten into the parenchyma from the upper surface of the 
leaves. It is a very shy little creature, and on the slightest dis- 
turbance jumps off and hides beneath the foliage. Young vineyards 
when infested should be promptly sprayed with a mixture of from 
5 to 8 pounds of arsenate of lead to 100 gallons of water. This 
gives the plants a very good protection. The earlier stages of this 
insect are not known. 

The grapevine Colaspis (Colas-pis brunnea Fab.) (fig. 7) in its gen- 
eral appearance resembles the grape root-worm beetle. It is, how- 
ever, slightly smaller, has no 
pubescence, and is of a pale yel- 
lowish color. It is nearly one- 
fifth of an inch long, with the 
body densely punctate. On the 





Fig. 6.— The redheaded Systena [System fron- Fig. 7.— The grapevine Colaspis ( Colaspis brunnea): 
talis): Adult or beetle. Much enlarged. Adult or beetle. Much enlarged. (Original.) 
(Original.) 

wing covers the deep punctures are arranged in double longitudinal 
rows or strise. The beetle feeds upon the grape foliage in a manner 
more or less similar to that of the grape root-worm beetle. 

It is not within the scope of this paper to treat the various insect 
problems, such as those of the grape leafhopper (Typhlocyba comes 
Say), the grapeberry moth (Polychrosis viteana Clem.), the grape cur- 
culio (Craponius insequalis Say), and others, which from time to time 
confront the vineyardist. These pests demand special treatment, 
and in cases of serious infestation an entomologist should be con- 
sulted. It has t however, been our observation that well cultivated 



DESCRIPTION. 



19 



and properly sprayed vineyards are less subject to the attacks of 
insects. Such infestations are very frequently the direct outcome of 
neglect in the general care of vineyards, as is more fully considered 
elsewhere in this bulletin. 



DESCRIPTION. 



THE EGG. 




(PI. I, figs. 3-4.) 



The eggs of the grape 
root-worm beetle are small 
yellowish - white objects, 
measuring 1.15 mm. in 
length and are about one- 
third as broad as long. In 
form the egg is cylindrical, with the two ends almost hemispherical. 
As the shell is very flexible and the eggs are generally laid crosswise 
on the canes, they often assume a slightly curved shape. Through 
the semitransparent shell the segmentation of the embryo can be 
seen, and later, as the young larva attains its full development, the 



Fig. 8. — The grape root-worm (Fidiaviticida). Larva: a, 
Side view of full-grown larva; b, front view of head; c, 
maxillte and labium. Much enlarged. (Original. ) 





Fig. 9. — The grape root-worm. Pupa: a, Upper view; 6, lower view; c, normal position of pupa in 
cell; c, d, showing the pupa supported by the spines in the cell; e, hind part of body, showing 
terminal spines. Much enlarged. (Original.) 

head with the dark-colored mandibles becomes clearly visible. Prof. 
F. M. Webster observed the 'larva backing out from the eggshell in 
the process of hatching. 

THE LARVA. 

(PI. I, figs. 5-6; text fig. 8.) 

The full-grown larva varies in length from 8 to 10 mm. It is 
whitish, with the head, thoracic shield, and spiracles pale brown. 



20 



THE GRAPE ROOT-WORM. 



The mandibles and the margin of the clypeus and areas around the 
antenna? are almost black. The anterior margin of the upper lip is 
armed with short and stout spines (fig. 8, b), and as the inner surface 
is reenforced by chitinous ridges extending inward, its function is 
probably that of a scraper. The setae on the head and on the cervical 
shield are rather prominent ; those on the sides and back of the body 

are less conspicuous. The 
ventral parts of the abdomi- 
nal segments are armed with 
strong spines, which are 
particularly large on the 
fourth to the eighth seg- 
ments. These project ob- 
liquely backward and are 
properly termed ambula- 
tory setae. The legs are 
slender and proportionately 
very small. Normally the 
larva assumes a curved posi- 
tion (fig. 8, a). The anterior 
portion of the body can be 
straightened out at will, but 
the hinder parts remain 
curved, which is character- 
istic of the larvae of most 
underground beetles. The 
newly hatched larva is little 
over 1 mm. in length and 
of slender form; the legs 
are relatively large, and the setae of the entire body are long and 
prominent. 

THE PUPA. 

(PI. I, figs. 7-9; text fig. 9.) 

The length of the pupa is from 8 to 10 mm. When newly trans- 
formed it is whitish, with a slightly pinkish tinge, which in a few days 
after pupation disappears and the pupa becomes white. The upper 
part of the head and anterior margin of the thorax are armed with 
large spines; each anterior and posterior femur is armed with one 
curved hooklike spine and two straight, more slender spines. The 
middle femora have only hairlike bristles. The posterior end of the 
abdomen carries two stout, flattened hooks, curved upward, and 
several pairs of spines and bristles (fig. 9, c and d). The pupa in the 




Fig. 10. 



-The grape root-worm: Adult or beetle, 
enlarged. (Original.) 



Much 



DESCRIPTION. 



21 



cell is supported by these larger spines and its body is not in touch 
with the moist walls of the cell. As these large and strongly chiti- 
nized spines do not occur in either the larval or the adult form of the 
insects, it is probable that 
their main function is to sup- 
port the pupa in the cell. 

THE ADULT OR BEETLE. 

(PI. I, figs. 1-2; text figs. 10, 11.) 



The original description of 
the beetle as made by Walsh 
is given below: 

Fidia viticida, new species. 
Chestnut rufous, punctured and 
densely covered with short grayish 
white prostrate hairs, so as to appear 
hoary. Head rather closely punc- 
tured, with a very fine longitudinal 
stria on the vertex. Clypeus and 
mandibles glabrous and black, the 
clypeus with a subterminal trans- 
verse row of punctures, armed with 
long golden hairs, the mandibles 
minutely punctured on their basal 
half. Palpi and antennae honey- 
yellow verging on rufous, the antenna? 
£ as long as the body, with joint 4 
fully £ longer than joint 3. Thorax 
finely and confluently punctured, 
about as long as wide, rather wider 
behind than before, the sides in a 
convex circular arc of not quite 60°, 
the males with the thorax rather 
longer and laterally less strongly curved than the females. Elytra punctato-striate, 
the striae subobsolete, the punctures approximate, and rather large but not deep, the 
interstices flat and with close-set fine shallow punctures. Legs with the anterior tibiae 
of the male suddenly crooked £ of the way to their tip; anterior tibiae of the female as 
straight as the others. Length $ .24-. 27 inch; $> .24-. 28 inch. 

The ovipositor of the female (fig. 11, d, e) consists of a more or less 
solid terminal portion and a membranous proximal part. Ordinarily 
it remains completely withdrawn within the abdominal cavity, where 
the terminal part lies within the membrane, which is folded into three 
parts. Meso-ventrally the membrane is supported by a slender chi- 
tinous rod (fig. 11, e). In the terminal portion are a pair of chitinous 
rods. Fully extended, the ovipositor is three times the length of the 
abdomen. 




Fig. 11. — The grape root-worm: Structural parts of the 
adult or beetle — o, Front view of head, showing biting 
mouth parts; b, lower view of labium and maxillae; 
c, antenna or "feeler;'' d, terminal portion of the 
ovipositor; e, ovipositor with membranous portion 
extended; /, front leg of male beetle; g, front leg of 
female beetle; h, claws of tarsus. All parts greatly 
enlarged. (Original.) 



22 THE GRAPE ROOT-WORM. 

SEASONAL HISTORY. 

The grape root-worm attains its growth during the feeding period 
of the larvse. The pupal stage, following the long larval period, is a 
process of transformation, whereby all the internal organs, and to 
some extent the external parts, become reconstructed, resulting, with 
the throwing off of the pupal skin, in the appearance of the beetle. 
It is during this latter stage and in the early part of the summer that 
reproduction occurs. 

The diagram (fig. 12) will, it is believed, greatly aid the reader in 
comprehending the development and the activity of the grape root- 
worm in its various stages throughout its life cycle. This illustra- 
tion has been compiled from both field and rearing observations 
and represents the life of a single beetle under average conditions. 

In the following consideration of the life history of the grape root- 
worm is presented the results of rearing experiments and field obser- 
vations for the year 1909. In most respects that year was normal 
as regards climatic conditions and the insect developed as might be 
expected under average conditions. In view of the extreme varia- 
tions in the development of the insect during 1907 and 1908, the 
records of observations for these years have been treated under 
the topic "Seasonal variations in the life history of the grape root- 
worm." The rearing and experimental methods relating to the tables 
of the life-history work are described separately on pages 44-50. 

THE ADULT OR BEETLE. 
THE PROCESS AND TIME OF EMERGENCE. 

Prior to its emergence the beetle spends several days in the pupal 
cell and at the time of the shedding of the pupal skin is of a light 
turbid yellowish cast, and is comparatively soft and for a time help- 
less. On an average the beetles remain 4 days in the cell, while the 
parts of the body harden. In Table XV (p. 38) are given 25 observa- 
tions on the length of time the beetles remain in the cell after trans- 
formation. In one instance a beetle remained in the cell 7 days. 
The minimum length of time was 2 days. Dead beetles have been 
found in cells, both in the breeding cages and in the ground in vine- 
yards. This occurrence, however, has not been found sufficiently 
common to cause any material reduction in the number of insects. 

The time required by the beetle in passing through the soil to the 
surface varies considerably with the distance to be covered and the 
texture and moisture of the soil. It has been possible to make only 
a few observations on the process of emerging. These were made in 
breeding cages with glass sides, in which the beetles have worked 
their way out to the edge of the soil next to the glass. One beetle 
which left the cell July 6 emerged July 9. On its way upward it had 



SEASONAL HISTORY. 



28 



to dig around a flat pebble, and as a result passed through 3h inches 
of soil. Another beetle left the cell July 5 and emerged July 6, having 
penetrated the soil for a distance of 1 inch. A third beetle left the 
cell July 16 and emerged July 19, in which time it worked through 2 
inches of soil. In the process of digging, the beetles make use of the 
mandibles and to some extent also of the legs. The cells become 
partly filled with earth by material being pushed behind and beneath 
the beetle. In this process the channel is refilled and only a small 
hole is left on the surface to indicate where the beetle emerged (PI. 




Fig. 12.— Diagram showing time and development of a single individual of the grape root-worm 
under average conditions, as observed in 1909, at North East, Pa. (Original.) 

I, fig. 10). In vineyards where the ground remains undisturbed such 
openings can be readily found during the emergence period of the 
beetle. 

In 1909 the first beetles observed in the field were collected by the 
senior author June 28, and, since daily observations were made of 
vineyard conditions, this record probably represents the earliest 
occurrence of the beetle for the season. In the breeding cases the 



24 



THE GRAPE ROOT-WORM. 



first beetle emerged July 1, which shows a fairly uniform emergence 
of beetles in captivity as compared with their emergence in the field. 
The results of the emergence experiments are given in Table I. 

Table I. — Date of the emergence of 398 grape root-worm beetles (Fidia viticida) from 
the ground, as observed in the breeding cages in the spring and early part of the summer 
of 1909 at North East, Pa. 



Date. 


Number 
of beetles. 


Date. 


Number 
of beetles. 


Date. 


Number 
of beetles. 


Date. 


Number 
of beetles. 


Julyl 

July 2 
July 3 
July 4 
July 5 
Jul'v 6 
July 7 
July 8 


5 
9 

16 
11 
15 
27 
34 
31 


July 9 
July 10.... 
July 11.... 
July 12. . . . 
July 13 
July 14.... 

July 15 

July 16 


36 
39 
19 
36 
22 
16 
26 
14 


July 17.... 

July 18. . . . 
July lit.... 
July 20. . . . 
July 2.'.... 

July 24. . . . 
July 25 


S 

4 
5 
2 

6 

1 
5 
2 


July 27. . . . 
July 29.... 
July 30. . . . 

Aug. 5 

Aug. 9 


4 
1 
2 
1 
1 










Total . . 


14S 


Total . . 


208 


Total.. 


33 


Total . . 


9 



In figure 13 the curve shows more graphically the relative emer- 
gence of these beetles. It will be noted from this curve that after 



1 i r~~l | "*1 ! 1 ' I i j ' ■ I ■ j ' . ' ■■ I )■ j ■[■ I" ■;- I :■■■[ .i 1 ':!'. it: I'. l 



h® 



j_^ 



K/i r-m/^^ c-^ 



22 23 i- 25 2fc 11 28 2* 



Fig. 13, — Curve showing time and relative emergence of beetles of the grape root-worm from the 
ground in rearing cages at North East, Pa., 1909. (Original.) 

the first emergence the beetles continued to appear in rapidly increas- 
ing numbers, reaching a maximum July 10. The decrease in the 
number of beetles emerging after this date was more gradual, and 
emergence continued until late in the season. In the cages the last 
beetle emerged August 9, while in the field a single beetle was still 
found in the cell August 14. From July 1 to July 5, inclusive, 14.1 
per cent had emerged; from July 6 to July 16, 75.4 per cent had 
emerged; and the remaining 10.5 per cent emerged later. Thus the 
great majority of over 75 per cent emerged during a period of 10 days, 
and the maximum of emergence took place about 2 weeks after the 
first beetle had been observed in the field. 



SEASONAL HISTORY. 



25 



VARIATION IN THE TIME OF EMERGENCE. 

The variation found in the time of emergence of beetles in different 
vineyards and even in different sections of the same vineyard is due 
to various factors, such as temperature, moisture, porosity and tex- 
ture of the soil, etc. 

Since larvse are found more abundantly in the looser porous soils 
than in the heavy, compact clay soils, and since the former soils are 
warmer, it is but natural that the insect should emerge earlier under 
these conditions. This fact is confirmed by observations presented 
in figure 14, which shows the relative emergence of beetles from three 
grades of soil. For these experiments a number of larvae were col- 
lected in the early spring from different localities in the vicinity of 
North East, Pa. They were confined in large earthen pots (fig. 22) 
with the same kinds of soil in which they had been collected. Since 
these larvse were supplied with a sufficient amount of food and the 




Fig. 14. — Curves showing variations in time of emergence of beetles of the grape root-worm from 
different kinds of soil. From rearing experiments during 1909 at North East, Pa. (Original.) 

pots were placed in the ground in the open, it is belieyed that their 
normal conditions had been changed but slightly. The emergence 
of beetles from the sandy and gravelly soil was seven days earlier 
than the emergence from the clay soil. 

In the vicinity of North East, Pa., the authors have observed that 
the emergence of the beetle in vineyards situated on the hills is one 
week later than the emergence in vineyards in the valley. This delay 
is not merely confined to the time of emergence of the beetles, but 
has been observed in practically all the different stages of the insect, 
as can be verified from the various tables of field observations. 



FEEDING BEFORE AND AFTER EGG DEPOSITION. 

At the time of emergence from the ground the beetle seems to 
possess a keen appetite. It readily finds its way to the grape foliage, 
and generally feeds upon the first leaf that it encounters. The leaves 
of the lower shoots are frequently found badly mutilated as a result 



26 



THE GRAPE ROOT-WORM. 



of this first feeding. The voracity with which newly emerged bee- 
tles feed is indicated in the poison -spray experiments described on 
page 65. Fifty per cent of newly emerged beetles were killed the 
first day, against 10 per cent of older beetles, both sets being sub- 
jected to identical conditions. 

The feeding of the beetle is confined mainly to the upper surface 
of the leaves; the parenchyma is devoured, leaving characteristic 
chainlike feeding marks, as shown in Plate II. With individual bee- 
tles the length of time of feeding previous to egg deposition varies 
considerably. In Tables II and III is given the record of 16 
individual females, showing a feeding period before oviposition vary- 
ing from 9 to 24 days, with an average of 15.9 days. 

Table II. — Oviposition, feeding , and length of life of individual male and female beetles 
of Fidia viticida in captivity during the summer of 1909 at North East, Pa. 



Number of experiment. 



Date of emergence of beetles . 



June 30 



June 30 



June 30 



June 30 



July 2 



July 2 



Mated 

First oviposition : . . 

Eggs 

Second oviposition . 

Eggs 

Third oviposition. . 

Eggs 

Fourth oviposition. 



July 8 
July 22 

31 
July 25 

31 
July 20 

40 
July 28 

25 



July 8 

July 21 

17 

July 26 

G 



July 8-9 
July 15 

20 
July 16 

10 
July 27 

14 
July 29 

01 



July 14 

July 21 

15 



July 13 

July 15 

17 

July 28 

14 

Aug. 3 

5 

Aug. 8 

4 



Fifth oviposition 

Eggs 

Sixth oviposition. . . 

Eggs 

Seventh oviposition. 

Eggs 

Eighth oviposition . . 

Eggs 

Ninth oviposition . . . 

Eggs 



July 19 

35 
July 26 

36 
July 29 

31 
July 31 

14 
4 

14 
7 

23 



Aug. 
Aug. 



Death of male. . . 
Death of female. 



Aug. 8 
Aug. 1 



Aug. 

Aug. 



Aug. 19 
Aug. 3 



July 
July 



Aug. 25 
Aug. 9 



Aug. 31 



Days of feeding before oviposition . 

Times of oviposition 

Eggs per cluster: 

Minimum 

Average 

Maximum 

Total number of eggs 

Length of life of male 

Length of life of female 



22. 

4.0 

25.0 
31.8 
40.0 
127.0 
39.0 
31.0 



21.0 
2.0 

6.0 
11.5 

17.0 
23.0 
57.0 
32. 



15.0 
4.0 

14.0 
30.0 
61.0 
120. 
50.0 
33.0 



21.0 
1.0 

15.0 
15.0 
15.0 
15.0 
23.0 
23.0 



13.0 
4.0 

4.0 
10.0 
17.0 
40.0 
54.0 
38.0 



17.0 
6.0 

14.0 
25.5 
36.0 
153.0 



60.0 



SEASONAL HISTORY. 



27 



Table II. — Oviposition, feeding, and length of life of individual male and female beetles 
of Fidia viticida in captivity during the summer of 1909 at North East, Pa. — Cont'd. 



Number of experiment. 



Date of emergence of beetles. 



Mated . 



First oviposition 

Eggs 

Second oviposition.. 

Eggs 

Third oviposition . . . 

Eggs 

Fourth oviposition. . 

Eggs 

Fifth oviposition 

Eggs 

Sixth oviposition . . . 

Eggs 

Seventh oviposition. 

Eggs 

Eighth oviposition . . 

Eggs 

Ninth oviposition . . . 

Eggs 



July 3 



July 14 

July 10 
14 



July 9 



jJuly 12 

1 to 15 

July 22 

25 
July 25 

51 
July 28 

43 
July 30 

33 
Aug. 



2 

2N 
5 
21 
7 
18 

Aug. 8 

15 

Aug. 13 

29 



Aug. 
Aug. 



July 10 



July 


14 


July 


14 


July 
July 


19 
19 
20 


July 
July 


22 
23 
26 



35 



July 10 



July 27 

-26 

Aug. 3 

43 
Aug. 6 

24 



July 11 



July 22 

July 27 

22 
July 29 

15 
Aug. 3 

28 
Aug. 5 

25 
Aug. 8 

11 
Aug. 9 

11 



July 12 



July 28 

Aug. 3 
35 



Death of male. . . 
Death of female . 



Aug. 25 
Aug. 23 



Aug. 10 
Aug. 23 



July 23 
July 24 



Aug. 14 
Aug. 26 



Sept. 
Aug. 



22 



Days of feeding before oviposition . 

Times of oviposition 

Eggs per cluster: 

Minimum 

Average 

Maximum 

Total number of eggs 

Length of life of male 

Length of life of female 



13.0 
1.0 

14.0 
14.0 
14.0 
14.0 
53.0 
51.0 



13.0 
9.0 

15.0 
29.2 
51.0 
263.0 
32.0 
45.0 



9.0 

2.0 

19.0 
27.0 
35.0 
54.0 
13.0 
14.0 



12.0 
5.0 

23.0 

32.8 
48.0 
164.0 
35.0 
47.0 



16.0 
6.0 

11.0 
18.6 
28.0 
112.0 
60.0 
42.0 



Aug. 
Aug. 



14 
6 

22.0 
1.0 

35.0 
35.0 
35.0 
35.0 
33.0 
25.0 



Number of experiment. 



Date of emergence of beetles July 12 



Mated 

First oviposition 

Eggs 

Second oviposition . . 

Eggs 

Third oviposition . . . 

Eggs 

Fourth oviposition . . 

Eggs 

Fifth oviposition 

Eggs 

Sixth oviposition . . . 

Eggs 

Seventh oviposition. 

Eggs 

Eighth oviposition.. 

Eggs 

Ninth oviposition . . . 

Eggs 



Death of male. . . 
Death of female . 



Days of feeding before oviposition. 

Times of oviposition 

Eggs per cluster: 

Minimum 

Average 

Maximum 

Total number of eggs 

Length of life of male 

Length of life of female 



July 27 
July 28 

25 
Aug. 1 

22 
Aug. 3 

35 
Aug. 5 

19 
Aug. 7 

10 
Aug. 11 

19 
Aug. 14 

18 
Aug. 19 

23 
Aug. 23 

23 



Aug. 25 



July 27 



Aug. 6 

57 
Aug. 8 

43 
Aug. 9 

25 

Aug. 13 

8 

Aug. 14 

37 
Aug. 17 

46 
Aug. 19 

16 
Aug. 20 

19 



July 27 



Aug. 28 
Aug. 26 



16.0 
9.0 

16.0 
22.2 
35.0 
200.0 



44.0 



10.0 
8.0 

8.0 
31.4 
57.0 
251.0 
32.0 
30.0 



Aug. 6 
Aug. 7 

20 
Aug. 8 

22 

Aug. 13 

4 

Aug. 18 

39 
Aug. 23 

28 



Aug. 14 
Aug. 27 



11.0 
5.0 

4.0 
22.6 
39.0 
113.0 
18.0 
31.0 



July 30 



Potals. 



Aug. 23 

35 
Aug. 26 

20 
Sept. 10 

29 
Sept. 14 

23 



Sept. 22 
Aug. 15 



24.0 
4.0 

20.0 
26.7 
35.0 
117.0 
54.0 
16.0 



416 
'362' 
'280' 
'294' 



120 



52 



52 



255 

71 



1,791 
553 
562 



Average. 



20. 
27*8 
25.' 5 
26." 7 
22.' 6 
'24.6 
"i7.*3 

i9.'6 

15.' 7 



15.9 
4.4 



112.0 
39.1 
35.1 



28 



THE GRAPE ROOT-WORM. 



Table III. — Summary of ori position experiments, recorded in Table II, showing the final 
average, maximum, and minimum, of egg deposition by individual female beetles in 
captivity, at North East, Pa., 1909. 



Observations. 



Number of days previous to first oviposition 

Number of times of oviposition 

Number of days between ovipositions 

Number of eggs per cluster 

Number of eggs per female 



Average. 



15.9 
4.4 
3.6 

24.0 
112.0 



Maximum. 



24 
9 
15 
61 
263 



Minimum. 



In Table V (p. 30), giving records of experiments with a large 
number of beetles in stock jars, where only the minimum length of 
time could be verified, this feeding period is shown to have covered 
from 9 to 10 days. Feeding is continued for almost the entire length 
of life of the beetle, and it has undoubtedly a direct bearing upon the 
number of eggs deposited. 

MATING AND ITS BEARING UPON EGG DEPOSITION. 

Mating of beetles has been observed a few days after their emer- 
gence. It has been found to take place several times before the first 
egg deposition, the day previous to oviposition, and also after each 
oviposition. Repeated mating, however, is not essential in bringing 
about further egg depositions, as shown in one instance under obser- 
vation (Table II, jar No. 13). In this jar the male and the female 
beetles were confined together shortly after emerging. Mating took 
place July 27, 28, and 30. The male beetle escaped August 5, yet 
oviposition by the same female occurred on August 7, 11, 14, 19, and 
23 without further mating. 

PROCESS OF EGG DEPOSITION. 

As the time of egg deposition approaches, the female beetles cease 
feeding for a day or two and become sluggish and somewhat inactive. 
They generally seek the shady places and are at this period to be 
found on the canes of the vines, where they are less easily detected. 

The eggs are deposited almost entirely under the loose bark on the 
canes and trunk ; very rarely, however, they are placed on other parts 
of the vine. The female inserts the eggs beneath the loose bark by 
means of the protrusible ovipositor (fig. 11, e) and places them side 
by side in a cluster of a single layer. An adhesive substance, secreted 
by the female, glues the eggs together, and the entire mass is fastened 
either to the cane or to the inner surface of the loose bark (PI. I, figs. 
3, 4). Individual female beetles have been observed to move along 
the canes in search of suitable places for egg deposition. In this 
process the hind end of the body touches the cane, and as the insect 
slowly passes along the ovipositor is inserted into the cracks or crev- 
ices, apparently testing the fitness of these places for egg deposition. 
A female beetle is shown in Plate I, figure 1, photographed in the act 
of oviposition. 



SEASONAL HISTORY. 



29 



VARIATION IN THE NUMBER OF EGGS PER CLUSTER. 

Under average conditions the eggs for each oviposition are all laid 
in a single cluster. In this respect exceptions occur when the female 
is disturbed in the act of oviposition or when the space is too small to 
hold all the eggs. On the other hand, it has been frequently found 
that eggs have been laid side by side by different females, so that 
from the appearance of the cluster separate depositions could not be 
told apart. In the breeding experiments clusters containing from 30 
to 35 eggs have been found quite frequently, and these figures repre- 
sent, approximately, the average number of eggs per cluster. Table 
II gives the egg deposition of 16 female beetles. As here there had 
been interference to some extent, and the beetles had been confined 
in captivity, the average number of 24 eggs per cluster was compara- 
tively low. The maximum number of eggs in one cluster was 61 and 
the minimum 4 (Table III). In the rearing cages the period for 
each separate oviposition occasionally extended over from 1 to 2 
days, rarely 3 days; normally, however, the eggs were all laid at 
once and in a single cluster. 

NUMBER OF SEPARATE OVIPOSITIONS BY INDIVIDUAL FEMALES. 

Different female beetles have displayed considerable diversity in the 
number of times of oviposition. In the experimental work 8 individ- 
uals failed to deposit any eggs ; others, as recorded in Table II, ovipos- 
ited from 1 to 9 times, or, on an average, 4 or 5 times. Similarly, the 
length of time between each oviposition is variable. An average of 4 
days elapsed between each oviposition. Often the interval has been 
only 1 day, while in the other extreme in one case the interval was 15 
days. (See Table IV.) 

Table IV. — Number of days between ovipositions of the grape root-worm as observed 
during 1909 in breeding cages at North East, Pa. (Supplementary to Table II.) 



No. of ex- 
periment. 


Periods between ovipositions. 


Total. 


Aver- 
age per 
female. 


I. 


II. 


III. 


IV. 


V. 


VI. 


VII. 


VIII. 


1 

2 

3 

4 


3 
5 
1 


1 


2 












6 
5 
14 


2.0 
5.0 
4.7 












11 


2 






















5 

6 

7 


13 

7 


6 
3 


5 
2 












24 
19 


8.0 
3.8 


4 


3 














8 

9 

10 

11 

12 


3 

4 
4 
2 


3 


2 


3 


3 


2 


1 


5 


22 
4 
15 
13 


2.7 
4.0 
3.7 
2.6 


1 
5 


7 
2 


3 
3 










1 














13 

14 

15 

16 

Total 
Average.. 


4 
2 
1 
3 


2 

1 
5 
15 


2 

4 
5 
4 


2 
1 
5 


4 
3 


3 

2 


5 
1 


4 


26 
14 
16 
22 


3.2 
2.0 
4.0 
7.3 




















52 

4.0 


53 

4.8 


37 
3.4 


21 
3.0 


14 

2.8 


7 
2.3 


7 
2.3 


9 
4.5 


200 


53.0 
4.07 



30 



THE GRAPE ROOT-WORM. 



NUMBER OF EGGS DEPOSITED BY INDIVIDUAL FEMALE BEETLES. 



The total number of eggs laid per female seems to depend upon the 
vitality of the individual insect, and undoubtedly also upon the 
amount of feeding by the adult. In the experiments of Table II 
the average was 112 eggs per female, with a maximum of 263 and a 
minimum of 14 eggs. In Table V is presented the results of the so- 
called "stock-jar" experiments, in which several beetles 
confined. 



were 



Table V. — Egg deposition of the grape root-worm by about 57 female beetles in eight 
stock jars, as observed in 1909 at North East, Pa.; with a summary of the length of 
life of the beetles for each stock jar. 



Stock jars. 


I. 


II. 


III. 


IV. 


V. 


VI. 


VII. 


VIII. 


Total 
num- 
ber of 
eggs. 


Number of 
beetles. 


25. 


21. 


5. 


22. 


16. 

July 13. 


12. 


7. 


6. 


Date of the 
emergence. 


July 9. 


July 10. 


July 11. 


July 12. 


July 16. 


July 19. 


July 22. 


Date of ovi- 
position: 
July 19... 
July 20... 


85 
















85 

105 

46 

237 

91 

100 

218 

226 

253 

104 

109 

163 

240 

42 

116 

158 

239 

282 

34 

55 

56 

75 

42 

42 

23 


105 
33 
44 
21 














July 21... 




13 
23 












July 22... 
July 23... 
July 25... 
July 26... 
July 28... 
July 29... 
July 30... 
July 31 . . . 
Aug. 1.... 
Aug. 3 


107 
70 
04 
96 
94 
43 
81 
22 

121 


38 


25 


















36 
33 

45 
74 










21 

27 
25 


68 








60 
39 










41 


31 




23 






29 


13 




35 

3 

143 

26 


10 






39 






35 


36- 


26 
16 
22 


Aug. 4 










Aug. 5 

Aug. 6 

Aug. 7.... 
Aug. 8.... 
Aug. 9.... 


28 
60 
35 
33 






52 


14 

28 
38 
29 
34 










70 
66 
36 








23 


- 77 
22 


10 




152 






Aug. 11... 
Aug. 13... 


17 












38 

'12 








16 
22 


10 
37 


18 


Aug. 14.. . 




16 






Aug. 19... 






19 
21 


23 
21 




Aug. 23... 














Aug. 27... 












23 


Total ovi- 
position 

Eggs per 
female. . 
















956 
76.5 


328 
31.2 


138 
55.2 


408 
37.1 


443 
55.3 


150 
25.0 


472 
134.9 


246 
82.0 


3,141 

55.1 



LENGTH OF LIFE OF BEETLES. 



Maximum 
number of 
days 

Average num- 
ber of days.. 

Minimum 
number of 
days 



50 


48 


23 


47 


53 


13 


46 


53 




21.6 


20.3 


12.0 


15.9 


23. 5 


5.0 


28.7 


20.2 




(', 


5 


.; 


3 


2 


3 


6 


1 





SEASONAL HISTORY. 



31 



The number of female beetles for each jar has been estimated to be 
at least half of the total number placed therein. The average number 
of eggs per female for each separate experiment varied considerably. 
In jar 7 there were approximately 135 eggs per female, in jar 6 only 
25 eggs per female, or a final average for the eight jars of only 55 
eggs per female. In considering the average egg deposition in the 
breeding cages there were found to be about 75 eggs per female. 

THE OVIPOSITION PERIOD FOR THE SEASON OF 1909. 

The oviposition period and the number of eggs deposited for the 
entire season is directly influenced by the time of emergence and 
occurrence of the beetles. In Table VI is given the total egg depo- 
sition of beetles in captivity. 

Table VI. — Records of the total egg deposition of the grape root -norm in breeding cages 
at North East, Pa., during 1909. 



Date. 


Eggs. 


Date. 


Eggs. 


Date. 


Eggs. 


Date. 


Eggs. 


July 8 
July 13 
July 15 
July 16 
July 18. 
July 19 
July 20 
July 21 
July 22 
July 23. 
July 25. . . . 

Total .... 


29 

83 
104 
153 

43 
155 
149 

88 
427 
121 
225 


July 26 
July 27 

July 29 

July 30 

July 31 

Aug. 1 

Aug. 2 

Aug. 3 

Aug. 4 

Aug. 5 

Total 


360 
62 
333 
379 
137 
123 
185 
28 
421 
71 
223 


Aug. 6 

Aug. 7 

Aug. 8 

Aug. 9 

Aug. 10 
Aug. 11 
Aug. 12 
Aug. 13 

Aug. 14 

Aug. 16 
Aug. 17 

Total 


291 

353 

397 

102 

19 

74 

29 

101 

152 

26 

46 

1,590 


Aug. 18 
Aug. 19 
Aug. 20 
Aug. 23 
Aug. 26 
Aug. 27 
Sept. 3 
Sept. 10 
Sept. 12 
Sept. 14 
Sept. 20 

Total 


39 
81 

19 
163 
20 
23 
40 
29 
22 
23 
15 


1,577 


2,322 


474 



Total number of eggs: 5,963. 

With the exception of a few early records, which were obtained 
from beetles collected in the field June 30, these records represent 
the total oviposition by the greater proportion of the beetles emerging 
in breeding cages (listed in Table I), and for their entire length of 
life. As the date of the emergence of these beetles was normal and 
simultaneous with the occurrence of beetles under natural conditions 
in the field, it is thought that this record of egg deposition may 
closely approximate oviposition in vineyards. In considering the 
relative number of eggs laid at different dates, it will be found 
(Table VI; fig. 15) that previous to July 22, 13.5 per cent were 
deposited; from July 22 to August 8, 71.4 per cent, and after August 
8, 15.1 per cent. Previously it has been shown how the time of 
emergence of the beetle varied, as a result of the development of the 
insect under different conditions. Thus oviposition in the same 
sections of the grape belt must differ under similar variations. The 
extreme of such variations has been especially marked in vineyards 



32 



THE GRAPE ROOT-WORM. 



located on the hill as compared with those in the valley. In Table 
XI is shown the time of hatching of eggs in the two named localities. 
On the hill the eggs were one week later in hatching, mainly as the 
result of later deposition. 




Fig. 15.— Curve showing time of egg deposition and relative abundance of eggs laid in rearing 
cages by beetles of the grape root-worm at North East, Pa., during 1909. (Original.) 

LONGEVITY OF MALE AND FEMALE BEETLES. 

On an average the beetles have lived in captivity one month. In 
Table VII will be found a full account of the length of life of individual 
male and female beetles. 



Table VII. — Length of life of individual male and female beetles of the grape root-worm 
as recorded in breeding cages at North East, Pa., during 1909. 



No. 


Sex. 


Date. 


Days. 


No. 


Sex. 


Date. 


Days. 


Emerg- 
ence. 


Died. 


Male. 


Fe- 
male. 


Emerg- 
ence. 


Died. 


Male. 


Fe- 
male. 


1 
2 
3 
4 
5 
6 

I 

9 

10 
11 
12 
13 
14 
15 
16 
17 
18 
19 
20 
21 
22 
23 


d" 

9 
3 
9 
3 

9 

3 

9 
3 
9 
3 
9 
3 
9 
3 
9 
3 
9 
3 
9 
3 
9 
3 


June 3( 
...do.. 
...do.. 
...do.. 
...do.. 
...do.. 
...do.. 
...do.. 
...do.. 
...do.. 
...do.. 
...do.. 
...do.. 
...do.. 

July 
...do.. 
do 


) 

i 


Aug. 4 
July 22 
July 26 
July 27 
July 22 
July 21 
Aug. 19 
Aug. 3 
Aug. 8 
Aug. 1 
Aug. 26 
Aug. 2 
July 22 
July 23 
Aug. 25 
Aug. 9 
Escaped. 
Aug. 31 
July 23 
July 24 
Aug. 10 
Aug. 23 
Aug. 27 


35 
26 
22 
50 
39 
57 
22 
54 


22 
27 
21 
34 
32 
33 
23 
38 


24 
25 
26 
27 
28 
29 
30 
31 
32 
33 
34 
35 
36 
37 
38 
39 
40 
41 
42 
43 
44 
45 
46 


9 
3 
9 
3 
9 
3 
9 
3 
9 
3 
9 
3 
9 
3 
9 
3 
9 
3 
9 
3 
9 
3 
9 


July 10 

...do 

...do.... 
...do.... 
...do.... 
...do.... 
...do.... 

July 11 
...do.... 

July 12 
.do. . 


Aug. 11 
Aug. 6 
Aug. 4 
Aug. 14" 
Aug. 26 
Aug. 23 
Aug. 24 
Aug. 22 
Sept. 9 
Aug. 9 
...do 


27 
35 
44 

42 

28 


32 
25 
47 
45 
60 
28 
44 
45 
41 
30 
31 
54 


...do.... 
...do.... 
...do.... 
...do.... 
June 15 
...do 


Aug. 5 
Aug. 25 
Aug. 6 
Aug. 26 
Aug. 25 
...do 


24 
25 
41 


...do.. 

July 
...do.. 

July 
...do.. 

July 1 




20 
32 

48 


60 
21 
45 


July 27 
...do.... 
...do.... 
...do.... 

July 30 
...do 


July 28 
Aug. 26 
Aug. 14 
Aug. 27 
Aug. 15 
Sept. 22 


1 
18 
16 



SEASONAL HISTORY. 



33 



The summary of these records (Table VIII) shows that the female 
beetles on an average, not individually, survived the males by 4 days. 

Table VIII. — Summary of the length of life of individual male and female beetles of 

Table VII. 



Sex. 


Average. 


Maximum. 


Minimum. 




Days. Days. 
32. 1 54 

3(i. 4 


Days. 
1 
21 


Female 









The maximum length of life for the males was 54 days, while that 
for the females was 60 days. In Table V is given further a summary 
of the length of life of the beetles in the stock jars, where no separate 
record has been made as to life of male and female individuals. 



THE EGG. 



INCUBATION PERIOD OF THE EGG. 



The time necessary for the hatching of the eggs depends largely 
upon the prevailing temperature and probably also upon moisture 
conditions. Experiments to test the effective limits of these influ- 
ences have not been made, but the results of these factors have been 
in a general way well marked as is evident from the difference in the 
time of hatching of individual egg clusters throughout the season 
(see Table IX). In different sections of vineyards the hatching 
probably varies slightly, since some eggs are located in well shaded 
places, while others are so situated as to receive more heat from the 
sunlight. In the middle of the hatching period eggs which were kept 
in an open outdoor shelter hatched, on an average, in 12 days. The 
rate for hatching for the entire egg period is shown in Table IX. 
51282°— Bull. 89—10 3 



34 



THE GRAPE ROOT-WORM. 



Table IX. — Incubation period of eggs of the grape root-worm as observed in 1909 at 

North East, Pa. 



No. of 
obser- 



Date. 



Laid. Hatched 



July 15 
...do... 

July 16 

July 18 
...do... 

July 19 

July 20 
...do... 

July 21 
...do... 

July 22 
...do... 

July 23 

July 25 

July 26 
...do... 

July 27 

July 28 

July 29 
...do... 
...do... 

July 30 
...do... 
...do... 
...do... 

July 31 
...do... 

Aug. 1 
...do... 

Aug. 2 

Aug. 3 
...do... 
...do... 
...do... 

Aug. 4 

Aug. 5 

..do. 

..do. 

..do. 

Aug. 

..do. 

..do. 

..do. 

Aug. 

..do. 

..do. 

..do. 

..do. 



July 

July 

..do. 

July 

Aug. 

..do. 

..do. 

Aug. 

..do. 

Aug. 

Aug. 

Aug. 

Aug. 

Aug. 

..do. 

Aug. 

..do. 

Aug. 

..do. 

Aug. 

Aug. 

Aug. 

Aug. 

Aug. 

Aug. 

Aug. 

Aug. 

..do. 

Aug. 

..do. 

..do. 

Aug. 

Aug. 

Aug. 

Aug. 

Aug. 

Aug. 

Aug. 

Aug. 

Aug. 

Aug. 

Aug. 

Aug. 

Aug. 

Aug. 

Aug. 

Aug. 

Aug. 



Days. 



No. of 
obser- 



Date. 



Laid. Hatched. 



Aug. 

Aug. 

. .do. 

..do. 

..do. 

..do. 

Aug. 

..do. 

Aug. 

..do., 

..do. 

Aug. 

..do. 

..do. 

..do. 

..do. 

Aug. 

..do . 

Aug. 

..do. 

..do. 

..do. 

Aug. 

..do. 

..do. 

..do. 

..do. 

Aug. 

..do. 

..do. 

..do. 

..do. 

..do. 

..do. 

..do. 

..do. 

Aug. 

..do. 

..do. 

..do. 

Aug. 

..do. 

Sept. 

Sept. 

Sept. 

Sept. 

Sept. 

Sept. 



Aug. 23 
Aug. 20 
Aug. 21 
Aug. 22 
Aug. 23 
Aug. 24 

...do 

Aug. 25 

...do.... 
Aug. 26 
Aug. 27 
Aug. 26 
Aug. 27 
Aug. 28 
Aug. 29 
Aug. 31 

...do.... 

"It:. 1 

Sept. 
Sept. 
Sept. 
Sept, 
Sept. 
Sept. 
Sept, 
Sept. 10 
Sept. 3 
Sept. 4 
Sept. 6 
Sept. 7 
Sept. 8 
Sept. 9 
Sept. 10 
Sept. 11 
Sept, 12 
Sept, 6 
Sept. 7 
Sept. 8 
Sept. 9 
Sept. 18 
Sept. 19 

Sterile. 

Sterile. 

Sterile. 

Sterile. 

Sterile. 

Sterile. 



Days. 



Table X. — Summary of Table IX; time of incubation of grape root-worm eggs for 1909. 



Incubation. 


Average. 


Maximum. 


Minimum. 


For the entire egg period 


Days. 
14.67 
12.3 


Days. 
24 
16 


Days. 
10 
10 


For the maximum egg period, July 22-Aug. 8, inclusive 



Eggs laid at approximately the same date by the same female 
varied in the time of hatching to the extent of several days. The 
embryological development becomes particularly prolonged later in 
the season with the advent of colder weather. All the eggs laid dur- 
ing the month of September failed to hatch. 

The rate of hatching of eggs in the field has been recorded in 
Table XI. 



SEASONAL HISTORY. 



35 



Table XI. — Field observations on the hatching of eggs of the grape root-worm in the 
valley and on the hill in the vicinity of North East, Pa., 1909. 



In the valley. 


On the hill. 


Date. 


Number 

of 
clusters 
counted. 


Percent- 
age of 
clusters 
hatched. 


Date. 


Number 

of 
clusters 
counted. 


Percent- 
age of 
clusters 
hatched. 


July 30... 
Aug. 4 ... 
Aug. 12.. 
Aug. 19.. 
Aug. 21).. 
Sept. 2... 


41 
70 
67 
90 
103 
78 


39 

42 
70 
91 
97 

100 


July 30... 
Aug. 13.. 
Aug. 19.. 
Aug. 26.. 
Sept. 2... 
Sept. 9.. 
Sept. 16.. 


48 
56 
76 
66 
97 
98 
87 


10 

40 
60 
77 
81 
92 
100 



THE LARVA. 



VITALITY OF THE NEWLY HATCHED LARVA. 

On hatching, the minute larva drops to the ground and makes its 
way to the roots of the vine through cracks and crevices in the soil 
and by burrowing. In this struggle to reach the food supply there 
is probably always a high percentage that perishes, for the number of 
eggs deposited is much larger than the number of larvae found later 
in the ground. 

The power of the young larva to exist for a time without food, 
however, is remarkable. In the breeding of the insect a number of 
newly hatched larvae, confined in a glass tube, were kept alive for 8 
days without food or moisture. Interesting experiments showing 
the burrowing and traveling powers of the young grub were carried 
out by Dr. E. P. Felt in 1902. This gentleman found that one larva 
had traveled a distance of over 47 feet in 7 hours, or an average of 
6 feet an hour. In another experiment he found that 14 young 
larvae out of 40 penetrated through loose earth in a glass tube 17 
inches long in a period of 4 days. This tube was one-half inch in 
diameter and bent so that 4 inches were vertical. In our breeding 
cages young larvae were found to feed upon the humus of the soil 
before reaching the root fibers; therefore it is not surprising that 
many larvae do penetrate to the roots, even under unfavorable con- 
ditions, and that they are found in vineyards in compact clay soil. 

FEEDING AND DEVELOPMENT OF THE LARVA BEFORE WINTERING. 

During the summer and until late fall the larvae feed extensively, 
and on an average attain three-fourths the full size and frequently 
full growth before wintering. 

The young larva feeds mainly upon the finer roots and root fibers 
of the grapevine. Later it attacks the larger roots, devouring the 
bark in longitudinal furrows, as shown in Plate III. Sometimes the 



36 



THE GEAPE ROOT-WORM. 



feeding may even extend to the underground portion of the stem. 
Most of the larvae are found within a distance of from 2 to 3 feet of 
the crown of the vine, and at a depth varying with the root system 
of the vines and the character of the soil. 

The rate of growth of the larva varies under different conditions. 
The time of hatching, the abundance of food, and the ease with which 
food can be obtained are determining factors. As a rule the larvae 
are found more abundantly in loose, porous soils, and especially on 
exposed ridges in the vineyards. (Table XII; fig. 14.) 



Table XII. — Occurrence of larvse of the grape root-worm in different soils, 
of field diggings for 1907, 1908, and 1909, at North East, Pa. 



Summary 



,„„_ (Mav 13-June8. 
1BU '-- \May31 



1909. 



/Mav 18-June9. 
\Juriel2 



fMay 24-June25. 
I Mav 19-June25. 
I Mav 27- Jul v 10. 
Umie 1-Julv 10.. 



Total 


Number 




Number 


number 


of vines 


Soil. 


of larvse 


of larva;. 


examined. 




per vine. 


831 


GO 


Gravel. . 


12 


1 


7 


Clay.... 


0.1 


96 


14 


Gravel.. 


6 


3 


3 


Clay.... 


1 


539 


88 


Silt a . . . 


6 


439 


83 


Gravel.. 


5 


102 


37 


Loam... 


3 


20 


54 


Clay.... 


0.4 



a Very light porous soil. 

From rearing and field observations we have found that the larvae 
are less abundant and slightly retarded in their development in clay 
soils. This is natural in that the larvae can not move about to obtain 
food in this soil so readily as in soils of looser texture. 

The growth of some larvae is sometimes delayed to such an extent 
as to hinder them from transforming at the normal period in the 
spring. Hence these belated larvae remain an additional year in the 
ground and transform in the spring of the second year. The causes 
of delay in the development and the percentage of belated larvae 
have been described in detail on pages 41-44. 



WINTERING OF THE LARVA IN AN EARTHEN CELL. 

As the time for hibernation approaches the grubs penetrate deeper 
into the ground, generally slightly below the roots of the vines. An 
earthen cell is made in which the larva spends the winter. It was 
observed in the field in the fall of 1909 that the 2-year-old larvae, 
referred to above, were the first to hibernate. Some of these were 
already in the wintering cells by the middle of August, when most 
of the larvae of the new brood were still extremely small or had not 
yet hatched. In Table XIII is shown the relative occurrence of 
larvae in wintering cells in the different vineyards. The actual 
percentage is higher than given, because in the process of digging 
many cells were broken, and thus escaped being noticed. 



SEASONAL HISTOKY. 



37 



Table XIII. 



-Percentage of hibernating larvae of the grape root-worm as found in 
vineyards during the fall of 1909 at North East, Pa. 



Curtis vineyard, in 
the valley. 


Algren vineyard, in 
the valley. 


Young vineyard, on 
the hill. 


Date of 
digging. 


Percent- 
age of 
larvse 

in cells. 


Date of 
digging. 


Percent- 
age of 
larvse 

in cells. 


Date of 
digging. 


Percent- 
age of 
larvaB 

in cells. 


Oct. 5.... 
Oct. 12. .. 
Oct. 19... 
Oct. 28. . . 


5 
20 
12 
83 


Oct. 4.... 
Oct. 14... 
Oct. 19... 
Oct. 25... 




14 
36 


Oct. 12... 
Oct. 20. . . 
Oct. 28. . . 
Nov. 12.. 



3 
16 
33 



SPRING FEEDING OF THE LARVA. 

In the spring, with normally developed larvae, comparatively 
little feeding takes place. In the early part of May, 1909, the 
larvse in the rearing cages were still in their wintering cells, and 
the condition in the field in most places did not permit the larvse to 
become active previous to that time. Since occasional pupal cells 
were found on May 24 in the field (Table XIV) and continued to 
appear in rapidly increasing numbers, the time of spring feeding 
may, on an average, have lasted 20 to 25 days. 

Table XIV. — Appearance of larva: of the grape root-worm in cells previous to pupation 

at North East, Pa., 1909. 



Date of 
digging. 


Soil 
condition. 


Total 
number 
of larva;. 


Number 
of larvse 
in cells. 


Percent- 
age of 
larvse 

in cells. 


May 19. . . 
May 24. . . 
May 25. . 


Gravel 

Sandy 

. .do 


230 
35 

140 
33 
32 
47 
79 
6 
7 

63 
54 






3 
37 
7 
2 
4 
23 


8.6 
2.8 

21.2 
6.2 
8.5 

29.1 


Do.... 

May 26. . . 
Mav 27. . . 
May 29. . . 
June 1. . . 

June 2 

June 3. . . 
June 4. . . 


Loam 

Gravel 

Clay 

Silt 

Clay 

Gravel 

Silt 

Gravel 


2 
25 
10 


2.8 
39.0 

18.5 



TIME AND MAKING OF THE PUPAL CELL. 

The pupal cells are found from 2 to 3 inches below the surface of 
the ground. Like the wintering cells, they are made by a peculiar 
rolling and twisting motion of the larva, whereby the cavity is 
enlarged, the earth becomes packed together, and the inside smoothly 
finished. The cell is quite spacious and would readily accommodate 
a larva twice the size of the owner. Usually 15 days are required to 
complete the pupal cell. As recorded in Table XVI, the average 
length of time spent by the larvae in the cell is 21 days, which includes 
the post-larval stage described below. Should the cell be disturbed 



38 



THE GRAPE ROOT-WORM. 



or destroyed some time before the post-larval period, a new one is 
readily made, and, as a rule, within a shorter time than was required 
for the making of the first cell. As recorded in Table XV, individual 
No. 21, a larva made the second cell and pupated within 9 days. 

Table XV. — Observations on the transformations and habits of the pupa and the beetle 
of the grapz root-worm in the soil, from breeding experiments at North East, Pa., 1909. 



Number of individual. 


Date. 


Days. 


Making 
of cell. 


Pupa- 
tion. 


Trans- 
formed 
to beetle. 


Left the 
cell. 


Making 
cell. 


Pupal 
stage. 


Beetle 
in cell. 


1 


May — 
May — 
May — 
May — 
May — 
May — 
May — 
May 30 
...do 


June 17 
...do.... 
...do.... 
June 15 
June 20 
June 19 
June 21 
.do.. . 


June 30 

July l 

July 2 
June 30 
July 7 
July 9 
July 10 
.do. . 


July 6 
( Died) . . 




13 
14 
15 
15 
17 
20 
19 
19 
12 
18 
15 
19 
19 
19 
18 
19 
19 
19 
18 
18 
20 
18 
20 
21 
17 
18 
18 
18 
17 
19 
21 
18 
19 
16 
18 
20 
18 
17 


6 


2 




3 


...do 






4 


July 5 




5 


5 




6 








7 


July 14 
do 




4 
4 


8 


22 
21 


9 


June 20 
June 21 
June 24 
June 20 
June 21 
...do 


July 2 
July 9 

...do 

...do 

July 10 
...do 


(Died).. 
July 13 
July 14 
July 13 
.do. . 


10 


May — 
May 30 
May — 
May — 
May — 
May — 
May 30 
.do 


4 
5 
4 
3 
4 
4 
7 
6 
3 
4 


11 


25 


12 


13 




14 


July 14 
July 13 
July 16 
July 13 

...do.... 

...do.... 




15 


...do.... 
June 20 
June 18 
June 21 

...do... 


July 9 

...do 

July 7 
July 10 
July 9 
...do 




16... . 


21 
19 
22 
22 
14 
9 

25 
14 
14 
31 
28 
28 
28 


17 


18 


.do. . 


19 


...do 


20 


June 7 
...do 


...do 


21 


.do. . . 


July 6 
July 12 
July 11 
July 13 
...do.... 
July 11 
do... 


July 13 
July 16 


7 
4 


22 


May 30 
June 7 
June 8 
May 26 
...do 


June 16 
June 24 
June 21 
June 22 
June 26 
June 23 
. .do 


23 


24... . 


July 16 

(Died).. 

July 14 

do. 


3 


25 


26 


3 
3 
3 

2 
4 


27 


. .do 


28 


...do 


.do. .. 


.do. .. 


29 




June 25 
...do.... 
June 2 
June 22 
June 23 
June 25 
June 26 
June 25 
June 29 
June 21 
June 10 
June 23 
...do 


July 12 
July 14 
July 23 
July 10 
July 12 
July 11 
July 14 
July 15 
July 17 
July 8 


do 


30 


May 30 
...do 


July 18 


26 
33 
23 
24 
21 


31 


32 


...do 






33 


...do 






34 


June 4 


July 17 


6 


35 


36 




July 17 




2 


37 






38 










39 


May 31 
June 5 

June 8 




10 
18 
15 




40 


July 11 


July 15 


18 


4 


41 


Total 












513 


696 


104 













Table XVI. — The making of the pupal cell, the pupal period, the beetle in the cell; 

summary of Table X V. 



Average. 



Maximum. 



Minimum. 



The making of the pupal cell 

Pupal stage 

Beetle in cell 



21.4 

17.8 

4.1 



Days. 



Days. 
9 
12 



THE POST-LARVAL STAGE. 



During the post-larval stage the grub undergoes marked structural 
changes and is in this condition extremely delicate and helpless. The 
body is slightly shortened, and the curved grublike appearance is modi- 



SEASONAL HISTORY. 39 

fied to a more cylindrical form. To some extent the legs become 
shorter and remain practically motionless. The white color changes 
to a light pinkish tint, which is especially marked toward the extremi- 
ties. Should the cell be destroyed during this period the larva is 
incapable of making a new one, and in many instances, as has fre- 
quently been observed in the breeding experiment, the larva fails to 
pupate. 

THE PUPA. 

THE PROCESS OF PUPATION. 

Pupation is the result of the changes brought about during the post- 
larval stage. In the process of pupation the larval skin splits on the 
back of the thorax and on the head, and the skin is ruptured along the 
median line and in front along the V-shaped suture toward the mouth 
(fig. 8, b). As the pupa frees itself from the larval skin it is of a 
rather elongated form. The appendages are short, and the skin on 
these parts is wrinkled in a circular manner. The light pink color is 
particularly marked on portions around the spines, head, prothorax, 
the points of the legs, and on the hind end of the body. The pupa is 
at this stage very restless, turning the abdomen in a circular motion, 
which, together with a contracting motion, brings about the expansion 
of the appendages and the assuming of the normal shape of the pupae. 
Unlike many pupae of beetles of this group, the larval skin is com- 
pletely freed from the pupa. Within a short time the pupa becomes 
whiter in color and the prominent spines turn darker as they harden. 

POSITION OF THE PUPA IN THE CELL. 

Within the cell the pupa is continually moving, often changing its 
position and constantly turning the abdomen in a circular manner. 
Normally the pupa lies on its back, and the soft body of the tender 
creature is kept from close contact with the moist walls of the cell by 
the spines on the appendages and on the back of the body (fig. 9). 
This function of the spines is undoubtedly of great importance in the 
development of the pupa, since this is the critical period of the insect, 
when the organs and in fact all the parts of the insect are recon- 
structed in the formation of the adult or beetle. The pupa is com- 
pletely helpless when removed from the cell and is incapable of 
making a new one, and if left on the surface of the ground or covered 
up with earth it almost invariably perishes. 

TIME OF PUPATION IN THE FIELD AND IN BREEDING CAGES. 

In the field during the summer of 1909 the first pupae were found 
June 11, while in the breeding cages the first pupa was found June 15. 
The time of pupation is indicated in Table XVII, showing the relative 
occurrence of the pupae in the field. 



40 



THE GRAPE ROOT-WORM. 



Table XVII. — Time of transformation of larvae and pupae of the grape root-worm in 
the field, as observed in the vicinity of North East, Pa., 1909. 



Vineyard. 


Date 

exam- 
ined. 


Number 
of vines 
exam- 
ined. 


Number 
of larvae. 


Number 
of pupic. 


Number 
of beetles 
in cells. 


J. D. Curtls's 

vineyard, 
porous silt. 


June 12 
June 21 
June 25 
June 30 
July 6 
July 10 




286 
6 
2 
2 


32 

47 

54 

4 




7 
6 
6 
6 
6 




2 

24 

4 












G.E.Pierce's 
vineyard, 
gravel soil. 


June 11 
June 21 
June 25 
June 30 
July 6 
July 10 




101 
5 
5 


49 
13 
12 




6 
6 
6 
7 
6 




3 

2 
















Vineyard, 

loamy 
soil. 


June 23 
June 25 
June 30 
July 7 
July 10 
July 17 


6 
6 

6 
6 

6 
6 


3 
1 
1 
1 


24 
5 

17 
2 
1 






2 
2 
1 










W hitman's 
vineyard, 
clay soil. 


June 23 
June 25 
June 30 
July 7 
July 10 
July 17 
July 26 


6 
6 
6 
6 
6 
6 
6 


1 
1 
1 
1 


6 
5 
2 








1 


1 




1 










1 



It is possible to establish the time of pupation by knowing the time 
of emergence of the beetle and the length of time of the pupal stage. 
Judging by the late emergence of the beetles, August 9, and by the 
finding of beetles in cells in the field August 14, pupae must have 
occurred up to the end of July. Based upon these records the curve 
of figure 23 has been constructed. 

DURATION OF THE PUPAL PERIOD. 

The pupal stage on an average lasts 17 days (see Tables XV and 
XVI). The maximum length of time observed was 21 days and the 
minimum 12 days. 

LIFE CYCLE OF THE GRAPE ROOT-WORM AS DETERMINED BY 

REARING. 

Several attempts were made to rear this insect from eggs, and to 
carry it through the different stages to complete the life cycle. In 
the course of these experiments many failures occurred. The mor- 
tality in certain experiments was high; in other instances a large per- 
centage became materially delayed in development and the larvae 
wintered a second season, and only a small number completed the 
life cycle within one year. (See Table XX.) The records from these 
latter observations are given in Table XVIII, with dates of hatching 
in 1908 and the dates of reaching maturity the following }^ear. 



SEASONAL HISTORY. 



41 



Table XVIII.— Complete life cycle of 19 grape root-worms at North East, Pa., reared 
from eggs laid during 1908; adults emerged in 1909. 



Num- 
ber of 
indi- 
viduals. 


Date of 


Number 
of days 
for the 

life 
cycle. 


Hatch- 
ing of 
eggs, 
1908. 


Emer- 
gence of 
beetles, 
1909. 


1 
1 
1 
1 
1 
4 
1 
4 
2 
1 
1 
1 


July 16 

...do 

...do 

...do.... 
...do 

July 20 
...do.... 

...do 

...do 

...do 

July 25 
...do.... 


July 9 
July 10 
July 13 
July 15 
July 17 
July 7 
July 8 
July 10 
July 11 
July 30 
July 26 
July 27 


358 
359 
362 
364 
366 
352 
353 
355 
356 
375 
366 
367 


19 




6,810 


i 



Average... 

Maximum . 
Minimum . 



Days. 
. 358.4 
. 375 

. 352 



SEASONAL VARIATIONS IN THE LIFE HISTORY OF THE GRAPE 

ROOT-WORM. 

In comparing the records for the time of emergence of the beetle 
for the three consecutive years of 1907, 1908, and 1909 a marked 
difference in the date of emergence will be found (fig. 16) . This varia- 
tion is partly due to the relative lateness of the spring and partly to 
the climatic conditions prevailing during the entire development of 
the insect in the ground. 

The climatic conditions for the years 1906 to 1909, inclusive, have 
been strikingly varied and, as will be seen, the life of the insect for 
these years has been affected accordingly. The mean temperature 
for 1906 was 1 degree above normal and the precipitation averaged 
about 1 inch below normal, August and September being particu- 
larly dry and hot. Frost occurred June 11 and 12 and snow on 
October 10, 11, and 12. The year 1907 was marked with an abnor- 
mally low temperature, a late spring, and an early fall, with a rather 
high precipitation for the summer months. The month of May was 
the coldest on record during a period of eighteen years. In 1908, on 
the contrary, the mean temperature was above normal and the 
summer was marked by two periods of severe drought, the dry condi- 
tions being especially felt during the end of August. In most respects 
1909 (fig. 17) was nearer the average. 

Although 1906 was a favorable season, during which the larvae 
attained a normal growth, yet owing to the late and cold spring of 
1907 the emergence of the insect was very materially delayed and 



42 



THE GRAPE ROOT-WORM. 



limited to a very short period (see fig. 16). The first beetle in the 
field was observed July 11. In the spring of 1908, on collecting 
larvae in different vineyards two distinct sizes were found, as possibly 
due to climatic conditions of previous seasons. The larger larvae 
were full grown, while the smaller varied from one-third to three- 
fourths grown. In the rearing cages the full grown larvae trans- 
formed normally and without further feeding. Of the smaller larva? 
few matured at the normal time, many were quite belated, while quite 
a number wintered, thus spending two years as larvae in the ground. 
As a result of the early season of 1908 the beetles commenced to 
emerge by June 16. The emergence extended over a long period; 



JUNE 

/5 20 25 J 


JULY 

5 /o /5 20 25 3 


AUG. 

5 /O /S 














J 


i 


i 


tltHTTT 


W. 












































fflllllll 


ntii 






lUnT 


mli ITT 











Fig. 16. — Diagram showing- variation in time of emergence of beetles of the grape root-worm during 
1907, 1908, and 1909 at North East, Pa. (Original. ) 

the latest beetles to emerge appeared in the rearing cages July 28. 
This longer emergence period was partly due to the delay in the 
development of larvae that hatched in 1907. In the spring of 1909 
the larvae were again of a more uniform size as a result of the long 
season of 1908, and the emergence in 1909, as recorded in figure 16, was 
about normal. On examining larvae in the field in the early fall of 
1909 data were obtained as to the prevailing number of 1-year and 
2-year old larvae (Table XIX). At the dates of these observations 
only a few of the new-brood larvae had attained one-half their growth 
while many of the eggs had not yet hatched, and since the 1908 brood 
larvae were full grown the two broods could then be readily told apart. 



SEASONAL HISTORY. 



43 



■h-tMt*- 

-Ttfffin! 




44 



THE GRAPE ROOT-WORM. 



Table XIX. — Percentage of 2-year-old larvse of the grape root-worm as recorded in 
vineyards in the vicinity of North East, Pa., in the fall of 1909. 



Vineyard in silt soil in the valley. 


Vineyard on loamy soil in the 
valley. 


Vineyard on gravelly loam on 
the hill. 


Date of 
digging. 


Num- 
ber of 
vines 
exam- 
ined. 


Total 
num- 
ber of 
larvae. 


Per- 
centage 
of old 
larva? . 


Date of 
digging. 


Num- T t , 

ber of * °^ ! 

vines : num " 

exam- ber of 
exam- i„ r „„ 

ined. lansc - 


Per- 
centage 

of old 
larva?. 


Date of 
digging. 


Num- 
ber of 
vines 
exam- 
ined. 


Total 
num- 
ber of 
larva'. 


Per- 
centage 
of old 
larva?. 


Aug. 17 

to 
Oct. 12 


1 32 


328 


3.0 


Aug. 16 

to 
Sept. 20 


1 18 449 


0.66 


Sept. 2 

to 
Oct. 7 


f" 


517 


5.0 



The percentages of twice-wintering larvae in Table XIX represent 
only records of early observations when a number of larvae had not 
yet been hatched. It is of interest to note that the percentage of 
2-year-old larvse was largest in vineyards located on the hill, owing 
to the prevailing shorter season on the hill as compared with the 
season in the valley. The time of transformation of the insects in 
other stages has similarly been affected by the climatic conditions of 
the past three years. 

In Table XX is shown the relative number of maturing insects and 
twice-wintering larvae which were reared from eggs deposited at 
known dates in 1908. 



Table XX. — The relative occurrence of transforming and twice-wintering larvse of the 
grape root-worm reared from eggs laid in cages in 190S, at North East, Pa. 



Date of hatching 
1908. 


Number of 

beetles 

emerging, 

1909. 


Number of 
larvae win- 
tering, 1909. 


July 16 


5 
12 

2 




12 


3 


July 20 

July 25 


July 28 

Total 


19 


15 



In the rearing experiments other factors beside climatic conditions 
have influenced the results and no direct conclusion should be drawn 
from these observations beyond the point of establishing the fact that 
under unfavorable conditions individual insects of this species do 
remain two years in the ground before maturing. 

REARING AND EXPERIMENTAL, METHODS. 

The underground habits of the larvae of the grape root-worm have 
made the rearing of this insect comparatively difficult, and certain 
obstacles have been overcome only by persistent and continued 
experimenting. The rearing work in most cases has been planned 



SEASONAL HISTORY. 



45 




Fig. 18.— Portion of the outdoor rearing shelter used in the rearing of insects at North East, Pa. 

during 1909. (Original.) 




Fig. 19— Wooden-frame box with glass bottom and wire-screen cover used in studying the pupal 
stage of the grape root-worm beetle. (Original.) 



46 THE GEAPE ROOT- WORM. 

on a large scale, so that variations would be minimized and the final 
averages would represent approximately normal conditions. The 
numerous separate experiments have involved the handling of a large 
bulk of rearing material, which, together with the simulation of nor- 
mal conditions, has to some extent necessitated special rearing 
devices and methods of handling. The experiments have been con- 



^^^^H 



Fig. 20.— Earthen pot with glass cylinder used in rearing the grape root-worm. (Original. ) 

ducted either in the field or under an open breeding shelter, a portion 
of which is shown in figure 18. This consisted of a temporary struc- 
ture of light wooden framework covered with waterproof canvas. 

Most of the rearing material was obtained in the spring, some time 
previous to the transformation of the larva?. During the past two 
years of the investigation the insects were to some extent reared 



SEASONAL HISTORY. 



47 



from eggs laid in the cages, and these larva?, together with larva? 
of the previous year, were carried through the winter in rearing 
cages. 

The pupal records have been obtained from experiments in medium- 
sized wooden boxes, having glass bottom, 9 inches long, 8 inches wide, 
and 5 inches high (fig. 19). Each box contained 2 to 3 inches of 
earth, and in order to duplicate outside weather conditions as nearly 
as possible the soil in these boxes was permitted to become almost 
dry during dry periods and during rainy periods water was propor- 
tionately added. To exclude the light from below, the boxes were 
placed upon burlap. Previous to the emergence of the beetles a 
wire screen cover was 
placed over each box. 
The shallow layer of soil 
caused many larva? to 
penetrate to the bottom 
of the cages, where they 
appeared next to the 
glass; and as the pupal 
cells, made of earth 
packed together, were 
next to the glass the 
activity of the insect 
inside could be readily 
observed. By means of 
a glass and porcelain 
blue pencil a number 
was fixed next to each 
cell, and by using this 
number a detailed rec- 
ord could be kept from 
the time the cell was 
made to the time the 
adult emerged. In the study of the underground habits of the insect 
the device shown in figure 20 proved to be useful. The glass cylin- 
der in the earthen pot was about half filled with soil, and to exclude 
the light the lower portion of the cylinder was wrapped with black 
paper. Several cells were made next to the glass, and on emerging 
the beetles were observed in the process of making their exit through 
the soil. 

Cages similar to the one shown in figure 21 were convenient for the 
study of the habits of the larva, and they were particularly useful 
in experiments extending over periods of one and two years. In width 




Fig. 21. — Rearing cage with glass sides used in the study of 
the larva of the grape root-worm beetle. (Original.) 



48 



THE GEAPE ROOT-WORM. 



these cages varied from 1 to 2\ inches, and were of a uniform height of 
20 inches. The two larger sides consisted of plate glass with outer 
wooden shutters on either side which could be removed for the exami- 
nation of the contents. 

The emergence records of Table I, as shown by curve in figure 
13, are the results of about 15 separate experiments with larvae 
transforming in large earthen pots filled with soil. Since the time 
of emergence of the beetles and their relative occurrence has a 

direct bearing upon the 
time of application of poison 
sprays against this pest, 
special attention and care 
were exercised in preparing 
these experiments. In the 
early spring approximately 
1,000 larvae were collected 
in different vineyards in the 
vicinity of North East, Pa. 
In many instances soil from 
different localities, which 
varied from loose sandy soils 
to heavy clay, was trans- 
ferred with the larvae to the 
rearing pots (fig. 22). Pro- 
vision for the spring feeding 
of the larvae was made by 
planting young grapevines 
in the pots. Finally the 
pots were placed in the 
ground in the open field and 
were left undisturbed for the 
rest of the season. Before 
the beetles commenced to 
appear wire screen covers 
were placed over each pot, 
so that a complete daily record could be kept of the number of 
beetles emerging from each separate pot. 

By preserving the beetles from the above-mentioned experiments, 
rearing material of known source and age was obtained for further 
experiments. The daily catch of beetles throughout the emergence 
period was transferred to so-called "stock jars," from which insects 
were taken as needed for miscellaneous experiments. The "stock 
jars" shown in the rearing shelter (fig. 18) consisted of large-sized 
glass jars covered with thin cloth. A layer of moist sand was placed 




Fig. 22. — Earthen pot with wire-screen cover used in rear- 
ing the grape root-worm. (Original.) 



SEASONAL HISTORY. 



49 



in each jar, which made it easier for the insects to move about and 
made the conditions more natural. Grape foliage, constituting the 
food of the beetles, was supplied daily, and to prevent unhealthy con- 
ditions in the cages the old leaves were always removed. For op- 
position short pieces of grapevine cane were placed with the beetles, 
and as egg depositions progressed these canes were removed daily 
and replaced by fresh ones. In determining the number of eggs 
deposited, the loose bark had to be peeled off the pieces of cane and 
the eggs in each cluster carefully counted. In determining the egg 
deposition of individual females and the length of life of male and 
female beetles, pairs when found in •opulation in the stock jars were 



MAY 

5 10 is io as 


JUNE 

5 >0 IS 20 25 


JULY 

5 10 15 20 2i 


AUG. 

5 10 IS S0 2S 


SEPT. 

5 10 IS 20 tS 


OCT. 

S 10 IS 10 is 


NOV. 

5 io IS 10 3S 












y 


i 


1 


1 


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PC 

Trrr 


DO 


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fltr 







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r 6 

■ — 


Cr 


Ci 





t 


£e 


'// 


t-S 


/- 


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>/r 


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tl 


tut 


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os. 


/> 


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of 


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trt 


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Fig. 23. — Diagram illustrating seasonal history of the grape root-worm as observed during 1909 at 

North East, Pa. (Original.) 

isolated previous to the earliest egg deposition. The observations on 
the habits of these individual beetles are given in Table II. 

Since the greater portion of the beetles from the emergence cages 
was used in obtaining the egg records, and since these insects ovi- 
posited undisturbed during the entire season, it is believed that the 
records in figure 15 represent the relative occurrence of eggs in the 
field. 

Eggs used in determining the length of time of incubation were 
kept in glass tumblers under the outdoor breeding shelter. 

In conjunction with the rearing work, field observations were con- 
stantly made, and in certain instances collections of the insect in its 
different stages were regularly made in the same localities for a given 
length of time. Thus it has been possible to check the rearing obser- 
51282°— Bull. 89—10 4 



50 THE GEAPE ROOT- WORM. 

vations with field conditions, and whenever differences have occurred 
corrections in the summary (fig. 23) have been made to approximate 
field conditions. 

SUMMARY OF LIFE-HISTORY STUDIES OF THE GRAPE ROOT- WORM. 

The life history of the beetle (see fig. 12, p. 23) may be briefly sum- 
marized as follows: The grape root- worm produces only one genera- 
tion a year; the larva feeds on the roots of the grapevine, and in this 
stage the insect is found in the ground for the greater part of the year. 
In early June the full-grown larva makes an earthen cell a few inches 
below the surface of the ground, within which it pupates about the 
middle of June ; the pupal stage lasts generally twenty days, and the 
beetle or adult begins to emerge from the ground in late June or early 
July, while a few belated beetles continue to appear in the early part 
of August. On an average the beetle feeds for from 10 to 13 days on 
the grape foliage before ovipositing. The eggs are laid beneath the 
loose bark on the canes of the vines, and hatch on an average in 12 
days; the young larva drops to the ground and soon finds its way to 
the roots of the vine ; generally the larva becomes three-fourths grown 
and sometimes attains its full growth in the fall. Previous to win- 
tering it penetrates deeper into the ground, below the roots, and there 
constructs an earthen cell in which it passes the winter. 

The diagram (fig. 23) shows the relative occurrence and the time of 
transformation of the grape root-worm in its various stages. It has 
been prepared from field observations and rearing records of 1909 and 
is a summary graphically presenting the life-history studies. 

Local variations in the times of development of the different stages 
of the insect, as described in preceding pages, may be brought about 
by various factors, such as differences in the texture of the soil, rela- 
tive abundance of food, and altitude and exposure of vineyards. 
The seasonal variations, as shown by the difference in the time of 
emergence of beetles during 1907, 1908, and 1909, and also by the 
occurrence of larvae that remained two winters in the soil, are the 
direct results of climatic influences. The insect has a strong tendency, 
however, to develop normally, even under adverse conditions. 

NATURAL ENEMIES. 
PREDACEOUS INSECTS. 

Several predaceous insects have been found feeding upon the larvae 
of the grape root-worm. During the process of digging for larva?, 
both in the spring and fall, various species of carabid beetles and their 
larvae have been found in the ground. These insects are entirely pre- 
daceous and probably feed upon the grubs of the grape root-worm 
whenever the latter come within their reach. Dr. E. P. Felt recorded 



NATURAL ENEMIES. 51 

Staphylinus vulpinus Nordm. as probably predatory on the larvse. 
In the spring of 1909 in one instance a "June-bug" larva {Lachnos- 
terna sp.) was found by the junior writer feeding upon a larva of the 
grape root- worm beetle. When first discovered the grape root-worm 
was already half devoured, and while the operation was being watched 
the remaining portion was completely eaten. 

The eggs of the grape root-worm are subject to the attacks of a 
number of different predaceous insects. Professor Webster observed 
in Ohio a small brown ant (Lasius brunneus Latr. var. alienus) and 
three species of mites (Tyroglyphus [Khizoglyphus] pliylloxerse [Riley], 
Heteropus [Pediculoides] ventricosus Newport, and the third, resembling 
Hoplophora [Phthiracarus] arctata Riley), feeding upon the eggs. Mr. 
P. R. Jones, of this Bureau, in 1907, at North East, Pa., found a 
coccinellid larva (Hippodamia convergens Guer.), and a malacoderm 
larva (family Telephoridae) feeding upon the eggs of the grape root- 
worm. The determinations of these coleopterous larvse were made 
by Mr. E. A. Schwarz, of this Bureau. The junior author in 1909, at 
North East, Pa., collected a small ant, determined by Mr. Th. Per- 
gande, of this Bureau, as Cremastogaster lineolata Say, var. ?, which 
carried off eggs from a cluster on a grape cane. The larvae of a lace- 
wing fly (Chrysopa sp.) have been observed from time to time extract- 
ing the egg contents by means <5f their pointed, tubelike mandibles, 
which are peculiarly well fitted for the purpose. 

PARASITIC INSECTS. 

Two minute hymenopterous egg parasites, Fidiobia jiavipes Ashm. 
and Lathromeris (Brachysticha) Jidise (Ashm.), were reared from eggs 
of the grape root-worm in Ohio by Professor Webster. The late 
Professor Slingerland recorded Fidiobia Jiavipes in the Lake Erie 
section in 1900, and later, during the present investigation by the 
Bureau of Entomology at North East, Pa., this minute egg parasite 
has been constantly noticed by different members of the staff. 
Lathromeris Jidise (Ashm.) has been only once observed at North East, 
Pa., as recorded on pages 56-57. The two parasites mentioned above 
were described by the late Dr. William IT. Ashmead a in 1894 from 
specimens reared by Prof. F. M. Webster. The original description 
of Fidiobia is given herewith: 

Fidiobia Jiavipes sp. n. Female, length, 0.6 mm. Black, polished ; legs and antennae 
yellow; thorax without distinct furrows, smooth, with only slight indications of furrows 
posteriorly, but not sharply defined ; wings hyaline, veinless; abdomen oblong, sessile, 
the first segment wider than long, the second very large, occupying most of the remain- 
ing surface, the following being usually retracted with it, and thus making the abdomen 
appear truncated at apex. 

aOinti. Soc. Nat. Hist, vol. 17, 1894, pp. 170-172. 



52 THE GEAPE ROOT- WORM. 

LIFE HISTORY OF FIDIOBIA FLAVIPES ASHM. 

During the summer of 1009 the junior author had opportunity to 
rear Fidiobia flavipes Ashm. (fig. 24) and to make some observations 
relative to its habits and occurrence in the Lake Erie grape belt. 

The parasitized root-worm eggs can be readily recognized in that 
they assume a brownish-j^ellow cast and become gradually darker 
with the development of the parasite. The grape root-worm eggs 
when first deposited are whitish, but soon take on a yellowish cast. 
In view of the semi transparent eggshell it is possible to observe the 
development of the different stages. 

Parasitized eggs were obtained in the vineyards July 13, from 
which adults issued on August 3. These adults were then placed in a 
vial August 4, with fresh eggs which had been laid in breeding cages 

the previous day. On August 7 an 
irregular area could be distinguished 
in the center of each egg, indicating 
a breaking up of the yolk tissue. 
On August 11 the parasitized eggs 
were already of a dark yellowish- 
brown cast. In one extremity of 
the egg there began to appear an 

Fig. 24. — Fidiobia flavipes, an egg-parasite of , ■ ij.11 l ] 

the grape root-worm: Adult and enlarged empty Space and the larva COllld 
antenna. Very greatly enlarged. (Orig- be distinguished feeding toward the 

inal) opposite end. On August 14 most 

of the parasite larva 1 pupated. Two or three days after pupation 
the eyes could be distinguished in the form of black spots, and a few 
days previous to the time of the emergence of the adults the entire 
pupa assumed a dark color. The minute hymenopterous flies emerged 
August 28, 20, and 30. 

In summarizing these data, we get 10 days for the egg and larval 
stages, 14 to 15 days for the pupal stage, or a total of 24 to 26 days 
for the whole life cycle. It is possible to recognize parasitized eggs 
3 or 4 days after they become infested. Adult insects lived from 5 
to 7 days in a test tube without food. 

To determine the development of parasites from root-worm eggs of 
different ages and also to test in a general way the resistance of eggs 
of different ages to parasitism, the following experiments were carried 
out as summed up in Tables XXI and XXII: 




NATURAL ENEMIES. 



53 



Table XXI.- 



-Parasitism, of grape root-worm eggs by Fidiobia flavipes at North East, 
Pa., 1909, the eggs ranging in age from 1 to 9 dags. 



Obser- 
vation. 

1 
o2 

3 
4 
5 
6 

7 
8 
9 


Grape root-worm 
eggs. 

Oviposi- Normally 
tion. hatching. 


Hatched. 


Parasit- 
ized. 


July 30 
July 31 
Aug. 1 
Aug. 3 
^ug. 4 
Aug. S 
Aug. 6 
Aug. 7 
Aug. 8 


Aug. 11 
Aug. 12 
Aug. 13 
Aug. 14 
Aug. 17 

...do 

Aug. 21 
Aug. 24 
Aug. 26 


X 
X 




X 
X 
X 
X 
X 
X 
X 
X 















a Parasites placed with the host August 9. New parasites emerged September 10 to 12. Thirty-two to 
thirty-four days to complete the life cycle. Experiment No. 2 consisted of 15 root-worm eggs, of which 13 
became parasitized and 2 eggs developed root-worms normally. Eggs within two to three days of hatching 
escaped parasitism. 

Table XXII. — Parasitism of eggs of the grape root-worm by Fidiobia flavipes, at North 
East, Pa., 1909, eggs varying in age from fresh to 10 days aid. 



Num- 
ber of 
obser- 
vation. 


Root-worm eggs. 


Num- 
ber of 
eggs. 


Emerg- 
ing root- 
worm 
larvae. 


Hatch- 
ing of 
para- 
sites. 


Oviposi- 
tion. 


Normally 
hatching. 


1 
2 
3 
4 
5 
6 
7 


July 25 
July 20 
July 28 
July 30 
Aug. 1 
Aug. 2 
Aug. 4 


Aug. 6 
Aug. 7 
Aug. 8 
Aug. 10 
Aug. 11 
Aug. 13 
Aug. 14 


15 
20 
38 
13 
18 
19 
22 


15 
20 






37 
12 
18 
19 
21 







Parasites placed with host August 4, having emerged August 3. New adults emerged August 30 to 
September 3. Twenty-seven to thirty-one days to complete the life cycle. Root-worm eggs within two 
to three days of hatching escaped parasitism. 

For each experiment egg clusters of the grape root-worm, each of 
a given age, ranging from 1 to 10 days, were subjected to the para- 
sites. The insects with the host were confined in large-size glass 
vials, which were covered with fine cloth. In Table XXI it is probable 
that the parasites oviposited shortly after being confined with the 
host, since they had emerged a few days previous to their confinement 
with fresh eggs. In the first experiment (Table XXI) the parasites 
were confined three days with the hosts. The two experiments of 
Tables XXI and XXII are practically identical, the second being made 
to check the results with those of the first one. The records for the 
normal hatching of the eggs are from another set of records, since 
such data could not be obtained from parasitized eggs. The results 
of either experiment show that the parasites did not affect eggs which 
were within two or perhaps three days of hatching. There was 
no marked difference in the time of the development of the parasites 
from eggs of different ages. 



54 THE GRAPE ROOT-WORM. 

The percentage of parasitized eggs in the field varied considerably 
in different sections of the grape belt, as well as in parts of the same 
vineyard. It was always highest where eggs were most numerous. 
This was especially brought out in the different sections in the experi- 
mental vineyards, where the sprayed areas were but slightly infested 
with root-worms. 

Thus, Davidson's vineyard, consisting of 12 acres, located half a 
mile north of the city, showed in 1908 the following results: 

Average 
number of 
Per cent eggs per 

parasitized. vine. 

Unsprayed young Concord vines 18 268. 8 

Sprayed young Concord vines 9. 5 12. 4 

Unsprayed old Concord vines 13. 2 319. 2 

Sprayed old Concord vines 20 23. 6 

Unsprayed Niagara vines 35 56. 

Sprayed Niagara vines Free. 1. 2 

The Porter vineyard, located a few miles east of the town and con- 
taining 1 acres of old Concord vines, gave the following results : 

Unsprayed plat had 14.7 per cent parasitized eggs. 
Sprayed plat had 5.5 per cent parasitized eggs. 

By comparing the records taken during August from three different 
vineyards located within a radius of from 2 to 3 miles east of N rth 
East, Pa., Algren's vineyard on August 4 showed 2 per cent of para- 
sitized eggs; Young's vineyard, August 24, showed 16 per cent; and 
Wheeler's vineyard, August 27, 96 per cent. 

A marked increase of parasitism was observed with the advance- 
ment of the season. The records given below, obtained by H. B. 
Weiss, from Mr. Young's vineyard, illustrate this fact: 

Per cent. 

July 30 5 

August 13 10 

August 19 14 

August 26 16 

September 2 20 

Similar records from other vineyards were not as uniform as those 
just given, but since the percentage varies with the amount of eggs 
present, no great uniformity can be expected unless the eggs are found 
more or less evenly distributed in the vineyards. 

By breeding the parasites two full generations and a partial third 
were produced. Infested eggs were obtained in the field July 1 3, from 
which adults emerged August 3. These were placed with fresh eggs 
August 4, and new adults issued August 28. The third generation 
developing from these adults was much delayed by cold weather, but 
at the time of concluding the field work for the season on November 
22 the adults were about to emerge. 



NATURAL ENEMIES. 



55 



The diagram (fig. 25) shows the relation of the three generations of 
parasites as observed in the breeding cages to the time of oviposition 
and the time of hatching of the host eggs. With the data in hand it 
is not possible to determine the period covered by each generation. 
The records only show the appearance of the first adults for the three 
generations. A few conclusions can, however, be drawn from the above 
diagram. Adult parasites must have existed in vineyards at the 
time of earliest oviposition of the grape root-worm. Adults producing 
the second generation appeared before the greater portion of the root- 
worm eggs had hatched, and since eggs could become parasitized 
within two days of hatching, the second generation is apt to infest 
more eggs than either the first or the third generation. In fact, the 
third generation appeared so late that it only reached a very few 
belated eggs. 

Fidiobia jlavipes is an important factor in the control of the grape 
root-worm. Professor Webster, who for several years studied the 




Fig. 25. — Diagram showing the relation between the three generations of the Fidiobia parasite and 
the relative occurrence of eggs of the grape root-worm at North East, Pa., during 1909. (Original.) 

grape root- worm in Ohio, reported in 1896 that the decrease in num- 
bers of the beetle was largely due to this and other parasites. Though 
the data on hand for North East, Pa., for the years 1907, 1908, and 
1909 are not sufficient to show any increase in occurrence, it is our 
impression, from extensive observations, that the insect is becoming 
more and more numerous. 



A DIPTEROUS PARASITE. 

Along with Fidiobia Jlavipes there occurs another grape root-worm 
egg parasite (fig. 26), which is at present only known in the larval 
stage. It is supposed to be a dipterous insect, in view of the resem- 
blance of the larva to dipterous forms. It was first observed by the 
senior author and Mr. P. R. Jones, of the Bureau of Entomology, who 
in 1907, at North East, Pa., collected several parasitized egg clusters. 



56 



THE GEAPE ROOT-WORM. 



During the summer of 1909 parasitized eggs were in evidence in 
the field from July 20 to August 30, and were found locally quite 
abundant, though less so than Fidiobia flavipes. Professor Webster 
informed the junior writer that he had found a similar parasite in 
Ohio in 1896. Table XXIII shows the relative occurrence of para- 




Fig. 26.— Larva of an undetermined insect parasite of the eggs of the grape root-worm. (Original.) 

sitized eggs as observed at various stages in different localities during 
1909 at North East, Pa. 

Table XXIII. — Percentage of eggs of the grape root-worm parasitized by a dipterous 
insect, as observed in vineyards in the vicinity of North East, Pa., 1909. 



Date. 


Vineyard. 


Per cent. 


Julv 20 
Julv 22 
July 24 
Aug. 4 
Aug. 12 
Aug. 19 
Aug. 2G 


Davidson 

Porter 

Mosher 

Algren 

do 

do 

do 


1 

1 

3 

7 

22 

12 

14 



It will be noted that there is an increase in the occurrence of the 
parasite toward the end of the season, as was observed with Fidiobia. 

Hoot-worm eggs parasitized by this insect are in their early stages 
opaque-white in color. Later the eggshell becomes semitransparent 
and iridescent. The larva of the parasite when full-grown is almost 
twice the length of the host and lies folded within the egg. The 
whitish larvae are very active on emerging from the hosts. They 
were found to penetrate several inches in the soil in glass jars. Though 
the larva is quite common, all attempts to rear the insect to obtain 
the adult or fly have so far proved fruitless. 

DOUBLE PARASITISM. 

August 30, 1909, a cluster of 115 root-worm eggs was collected, 
which were infested by the dipterous parasite. The egg along the 
border of the cluster, unlike the rest, a few days later assumed a pink 
color, but at the same time showed the iridescence characteristic of 
this parasite. Dipterous larvae emerged September 3 from the eggs 
of the central portion of the cluster. From the eggs along the border 
of the cluster a hymenopterous fly (Lathromeris fidise. Ashm.) (fig. 27) 



VINEYARD CONDITIONS IN LAKE ERIE VALLEY. 57 

emerged. The host had been confined indoors during the winter, 
thus bringing out the hymenopterous parasite on February 2. It is 
probable that the root-worm eggs were first parasitized by the dip- 
terous insect and that later the eggs along the margin of the cluster 
were parasitized a second time by Lath- 
romeris Jidise. The dipterous and the 
hymenopterous insects are undoubtedly 
both primary parasites. 




VINEYARD CONDITIONS IN THE 
LAKE ERIE VALLEY. 

Fig. 27.— Lathromer is fidise, an egg-para- 

Before entering Upon a discussion Of site of the grape root-worm: Antenna 

,i i n , i i , i • , and fore wing. Verv greatly enlarged. 

methods of control undertaken against (original ) 
the grape root-worm during this inves- 
tigation it may be well to consider some of the changes which have 
occurred in vineyard conditions throughout the Lake Erie valley since 
the advent of this pest. 

In 1900, when the grape root- worm first appeared in injurious 
numbers in the Lake Erie valley, the grape industry was just emerging 
from a period of depression which had caused, for several years pre- 
vious, an almost complete cessation in planting of new vineyards. 
The period of low prices had resulted in indifferent care, amounting 
in some cases to positive neglect, thus creating a condition very 
favorable to the increase of this pest. Furthermore, the fact that 
practically all vineyards had been for several years in bearing and 
had a well established root system permitted the insect to become 
thoroughly disseminated through them before the unsuspecting 
owners were aware of its presence in numbers sufficient to affect the 
vigor of their vines. The tendency of most vineyardists at that 
time was to pull out declining vineyards rather than to go to 
the expense of fighting insect foes. Thus it happened that a com- 
bination of circumstances conspired to favor a general spread of the 
insect without creating widespread alarm. 

With the steady rise in the value of grapes since 1900, however, 
this condition has been reversed. Thousands of acres of new vine- 
yards have been planted, and the more progressive vineyardists are 
commencing to appreciate fully what an enormous amount of injury 
has been done to their old vineyards, and are greatly alarmed at the 
rapidity with which many young vineyards are falling a prey to this 
pest. 

The maximum crop yield for the Lake Erie grape belt occurred in 
1900, and amounted to 8,000 carloads of fruit. At that time there 

a The authors are indebted to Mr. A. A. Girault, of the office of the state entomologist 
of Illinois, for the determination of the above-named parasites. 



58 THE GRAPE ROOT- WORM. 

were about 30,000 acres of vineyards in bearing. Since 1900 fully 
10,000 acres of bearing vines have been added to this area, yet the 
yield for 1908 was only a little more than one-half that of 1900. 

The figures given below are taken from the Chautauqua Grape 
Belt, a newspaper which is largely devoted to the grape interests 
of that region and every year publishes carefully gathered statistics 
on grape production. 

Grape production from 1900 to 1909. 
Yield for— Carloads. 

1900 8, 000 

1901 6, 669 

1902 5, 062 

1903 2, 954 

1904 7, 479 

. 1905 5, 365 

1906 5, 465 

1907 5, 186 

1908 4, 232 

1909 7, 561 

These figures denote a steady decline in crop yield traceable to a 
variety of causes, namely, depletion of soil, lack of proper cultivation, 
adverse weather conditions, and lack of proper fertilization. There- 
are thousands of acres of vineyard throughout the belt that have 
borne many crops and have never received a pound of fertilizer. It 
is doubtful, however, if all of these factors combined could of them- 
selves have resulted in such unfavorable vineyard conditions as have 
been brought about by the ravages of the grape root-worm. "We 
make this statement advisedly after several seasons of careful study 
of the habits and depredations of the pest. 

The table presents certain points of interest. .Thus, in 1903 there 
was an especially light crop of 2,954 carloads followed by a large 
crop in 1904. About the same conditions prevailed during the 
respective years 1908 and 1909. It should be borne in mind that a 
considerable percentage of the phenomenal increase during the years 
1904 and 1909 must be credited to the greater vigor of the plants 
following the light crops of the preceding years and to extremely 
favorable weather conditions. 

In the early history of this infestation, as previously mentioned, 
practically all of the vineyards of the belt contained old vines with a 
well-established root system able to withstand for several seasons even 
a heavy infestation of the larvse before a marked decrease in yield 
was noticeable. With the extensive planting of new vineyards since 
the thorough dissemination of this pest its swift and deadly work 
has become more apparent. Numerous instances have come to our 
notice where young vineyards bearing the second or third season's 
crop have been so severely injured that hundreds of vines died 



REMEDIAL MEASURES. 59 

outright in a single season, while the rest were so weakened that they 
had to be cut back so severely that in the following season they were 
unable to produce more than from 15 to 25 per cent of a normal 
crop. Persons not thoroughly familiar with the habits of the pest 
have frequently charged this death and weakened condition to a 
variety of causes, such as winter killing, deep plowing, overbearing 
of young vines, etc. In practically every case of this kind coming 
under our observation we have found overwhelming evidence of 
injury wrought upon the roots by the larvae of this pest. There is 
no doubt that the overbearing of young vines which possess a limited 
root system and then become subject to a heavy infestation of grape 
root-worm larva? will serve to greatly weaken the vine, and that 
severe winter weather following this heavy infestation of larvae, and 
consequent weakening of the vine, will accelerate the death of the 
vine during the winter. Yet these are but secondary evils to which 
the vines, primarily weakened by injury from the insect during the 
growing season, finally succumb. This is also true of drought condi- 
tions occurring in August and September. During the drought 
which occurred in these months in 1906 numerous cases came under 
our notice where young vines bearing a heavy crop of fruit and having 
made a heavy growth of vine early in the season .were so badly 
injured by larvae hatching from eggs deposited in July that they 
were unable to mature the fruit, which actually shriveled on the vine 
by the last week in August. Other injured vines which carried 
through their crop died during the following winter. It is the rapid 
decline in yield of large numbers of vines in young vineyards through- 
out the whole grape belt and the steady though less perceptible 
shrinkage in yield of the other vineyards that make it impossible 
for the increased planting of recent years to more than hold its own 
with the crop production of the period previous to the general infes- 
tation of vineyards by this pest, and it will require the greatest care 
and watchfulness on the part of those planting new vineyards to 
carry their young bearing vines through that critical period when 
they are producing their first two or three crops and at the same 
time establishing a root system sufficient to continue the production 
of successive profitable crops. 

REMEDIAL MEASURES FOR THE CONTROL OF THE GRAPE ROOT- 
WORM. 

EVOLUTION OF PREVENTIVE MEASURES. 

Although the occurrence of this insect in numbers sufficient to 
cause great damage to the foliage of grapevines was brought to the 
attention of Walsh in 1866, no remedial measures were suggested by 
him. The first record of an attempt to control the pest was made 



60 THE GRAPE ROOT-WORM. 

in 1870 by C. V. Riley, who relates an instance where a vineyardist, 
having observed that the beetles have the habit of falling from the 
foliage to the ground when the vines are jarred and that they have a 
tendency to "play possum," and also that they were readily devoured 
by his chickens, was able to destroy many of them in his vineyard 
by having a boy drive his flock of chickens through the vineyard 
while he shook the beetle-infested vines in front of them. 

In 1872 Kridelbaugh suggested handpicking of the beetles from 
the vines and also the use of an arsenical spray. 

Not until 1895, however, when Professor Webster made his inves- 
tigation of the pest in Ohio, were methods for its control seriously 
considered. During his investigation Professor Webster conducted 
experiments with salt, kainit, tobacco, kerosene emulsion, and carbon 
bisulphid against the larvae in the soil, all of which appear to have 
given indifferent results. The carbon bisulphid, although partially 
effective, was likely to injure the roots of the vines and was also 
too expensive to be practicable. He also used kerosene emulsion 
against the adults, both on the foliage and after they had fallen to 
the ground. Pyre thrum in solution was used in the same manner, 
but with very indifferent results. Arsenical sprays were applied to 
the foliage in an attempt to poison the beetles, using London purple 
and Paris green, 4 ounces to 50 gallons of water, and arsenate of lead, 
1 pound to 150 gallons of water. Although there was evidence that 
some beetles were destroyed by the use of these arsenicals, the results 
were far from conclusive. Later experiments in Ohio with arsenicals 
against the pest gave more encouraging results, yet the practice of 
spraying as a method of control never became general. Therefore 
in 1900, when the insect appeared in destructive numbers in the 
vineyards of Chautauqua County, N. Y., it was again the subject of 
experimentation by both the late Prof. M. V. Slingerland, of Cornell 
University Agricultural Experiment Station, and by Prof. E. P. Felt, 
of the New York State Museum to determine effective methods of 
control. 

During the early part of the investigation it was shown that early 
in June the larvae come near the surface of the soil to make the pupal 
cells in which they transform to beetles, and that thorough stirring 
of the first 3 or 4 inches of the soil, especially beneath the trellis, will 
expose and destroy a large number of the pupae. On account of the 
somewhat unsatisfactory and inconclusive results obtained with 
arsenical sprays in former years in Ohio, Doctor Felt gave consider- 
able attention to the perfecting of a device for collecting the beetles 
by jarring them into troughlike receptacles containing kerosene oil 
which could be operated either by hand or by horsepower where 
large areas of vineyard have to be treated. That large numbers of 
the beetles can be captured and destroyed by this method is demon- 



REMEDIAL MEASURES. 



61 



strated in Doctor Felt's reports of his experiments published by the 
New York State Museum. (See Bibliography, p. 93.) 

Experiments with arsenical sprays against the pest during the 
early part of the New York investigations, although giving more 
encouraging results than those obtained in Ohio, were not so con- 
clusive as could have been desired. By persistent experiment with 
improved spraying apparatus and increased strength of arsenicals, 
and thorough and heavy applications where desirable, Professor 
Slingerland was able toward the end of his investigations to secure 
results with poison sprays which showed that in the hands of the 
thorough vineyardist very effective results could be obtained. 

Unfortunately these field experiments with arsenicals were not 
conducted for a number of consecutive seasons on the same blocks of 
vineyards. This makes it impossible to determine the cumulative 




Fig. 28. — Horse hoe used in removing the soil from beneath the trellis in vineyards. (Original.) 

benefits of the treatments in preventing infestation on the sprayed 
portion as compared with the injury wrought by the insect on the 
untreated portion of the vineyard. 



CULTURAL METHODS FOR THE DESTRUCTION OF PUPiE. 

Prior to the appearance of the grape root-worm in destructive 
numbers in the Lake Erie grape belt about the first cultural operation 
of the season performed by vineyardists was to remove the soil 
from beneath the trellis with a horse hoe (fig. 28) to a depth of 3 or 4 
inches. This operation removed all of this layer of soil beneath the 
trellis with the exception of a few inches directly around the base 
of the vine which was removed later with a hand hoe. Almost 
immediately following these operations a furrow was thrown back 
under the trellis with a 1 -horse plow, and the remaining space between 
the rows of grapes was stirred with a gang-plow and followed by sev- 
eral cultivations during the season. With the discovery that the 
grape root-worm larva has the habit of coming near the surface of 



62 THE GRAPE ROOT-WORM. 

the soil to make its pupal cell, this plan of cultivation has been some- 
what modified. In order to encourage the larva to come still higher 
above the roots of the vine to pupate than it would have done under 
ordinary cultural methods it has become customary to throw up a 
ridge of soil beneath the trellis at the last cultivation of the preced- 
ing summer (see PI. V, fig. 2). Observations have shown that it is 
highly desirable that this ridge be formed under the trellis late in the 
summer rather than in the early spring, since in the former case the 
soil becomes of a uniform compactness by the time the larvae are 
ready to migrate nearer to the surface to pupate; whereas, if the 
ridge is formed in the spring a layer of trash and leaves accumulating 
under the trellis during the winter is sandwiched in this ridge, and in 
no case in our examinations have we found pupal cells above this 
layer of trash. In the operation of horse hoeing this spring -formed 
ridge away from the vines it frequently happens that only the layer 
above the trash is thrown away, hence the pupae, which are all 
beneath the trash, are undisturbed. 

Undoubtedly this modification in the plan of early cultivation of 
vineyards is an important aid in the destruction of this pest at a 
time when it is in its most critical stage of development. Instances 
have come directly under our observation where we have seen great 
numbers of the pupae exposed to the air and sunlight or become the 
immediate prey of birds and predaceous insects. The operation is 
probably of greater value in sandy and loose gravelly soils than in 
stiff clay soils, for in the former the earthen cells fall apart quite 
readily with the disturbance of the soil, leaving the pupae exposed; 
whereas in the clay the soil is more likely to turn over in lumps, leav- 
ing many of the cells intact. In addition to this, in soils of a sandy 
or gravelly nature the loose earth around the vines may be removed 
by the horse hoe to a much greater depth and more pupae disturbed 
than in the case of sti|f clay soils, where it frequently happens that 
the operation of horse hoeing amounts to little more than a scraping 
of the weeds from the surface of the ground, especially if the season 
be a dry one. In fact, the drying out of the soil is the chief draw- 
back to placing reliance on this operation as a means of controlling 
this pest. 

It not infrequently happens that a dry period may occur along the 
Lake Erie Valley during the month of June which renders it difficult to 
make horse hoeing as thorough and as timely as it should be to derive 
the greatest benefit from this operation in the destruction of the 
pupae. In the summer of 1907 when the development of the pupae 
was unusually late the operation of horse hoeing was postponed by 
some vineyardists until the last of June and early July in order to 
perform it at a time when the maximum number of the insects were 
in the pupal stage, and considerable complaint was forthcoming 



Bui. 89, Bureau of Entomology. U. S. Dept. of Agriculture. 



Plate V. 




Ridge of Soil Under Trellis. 

Fig. 1. — Vineyard view in the spring, showing ridge of undisturbed soil under the trellis. 
Fig. 2.— Vineyard view, showing ridge of soil under trellis as formed at the last cultivation 
of the preceding summer. North East, Pa. (Original.) 



REMEDIAL MEASURES. 63 

from large vineyardists concerning the undesirability of suspending 
horse hoeing until so late a date. In 1907 we saw many hundreds 
of acres of vineyard in the condition shown in Plate V, figure 1, in 
which cultivation had been suspended to await the development of 
the pupae. Under normal conditions this cultivation would have 
been performed several weeks earlier, and since early and thorough 
tillage is essential to good vineyard management, it is not well to 
place entire reliance On this operation to control the pest. Never- 
theless it is an operation that should be utilized whenever soil and 
moisture conditions will permit, and these are most favorable in 
sandy and gravelly soils and in seasons of moderate rainfall during 
the month of June. The most beneficial results from this operation 
are obtained by horse hoeing as deeply as possible without scraping 
the roots, followed by thorough and deep hand hoeing around the 
crown of the vine, at which point by far the greater number of pupae 
are to be found. 

During this investigation we have never felt warranted in placing 
entire dependence upon this method of destroying pupae to control 
this pest, but have regarded it as a valuable supplementary aid 
obtained by a slight modification of general vineyard practice at no 
additional expense to the vineyardist and that other means must be 
employed to destroy the beetles developing from pupae which escape 
destruction by this method. Since we were unable to find vineyard- 
ists with heavily infested vines who were willing to allow us to con- 
duct an experiment covering several acres for several consecutive 
seasons, depending entirely on the destruction of pupae by cultivation, 
it is impossible to present definite data as to the exact value of this 
treatment. 

EFFECT OF POISON SPRAYS ON THE BEETLE IN THE FIELD. 

The use of poison sprays against the beetles of the grape root-worm 
after they have emerged from the soil and commenced to feed upon 
the foliage of grapevines has been recommended by many ento- 
mologists since the insect has become of economic importance as a 
vineyard pest. 

Extensive experiments with arsenicals were made by Webster in 
Ohio in 1895, and also by Slingerland and Felt in Chautauqua County, 
N. Y., in a number of field experiments conducted during the seasons 
from 1902 to 1906. 

Although in many of these experiments the results obtained indi- 
cated a considerable degree of benefit from the use of arsenical poi- 
sons, especially in those made by Slingerland from 1904 to 1906, there 
has always been an element of doubt as to the value of arsenical 
sprays applied to the vines as a direct and rapid killing agent of the 
beetles. The inference has been drawn by some experimenters that 



64 THE GRAPE ROOT-WORM. 

the beneficial effects of poison sprays are due rather to a distaste on 
the part of the beetles for poisoned foliage, and their consequent 
abandonment of sprayed foliage and migration to unsprayed areas, 
than to the direct killing effect of the poison. This view is supported 
to some extent by cage experiments which showed that in many 
cases when confined in cages the beetles fed but slightly upon spraved 
foliage and the death rate was not as rapid as might be wished. In 
addition to this, beetles thus confined with poisoned vines have in 
feeding indicated a preference for unsprayed areas, all of which left 
reasonable cause for doubt as to the direct efficiency of arsenicals as 
a killing agent. 

During our investigation of this pest, covering the seasons of 1907, 

1908, and 1909, we have observed this tendency of the beetles to feed 
more freely upon the unpoisoned than upon poisoned foliage, both 
in the open vineyard and in cages, yet we have no direct evidence of 
wholesale migration of the beetles from sprayed areas. 

CAGE EXPERIMENTS WITH POISON SPRAYS AGAINST THE 

BEETLES. 

On July 13, 1907, 100 beetles recently emerged from the soil were 
divided into two lots of 50 each and placed in cages; one cage con- 
tained sprayed foliage collected from a vineyard recently sprayed, the 
other unsprayed foliage. The beetles in the cage containing the 
unsprayed foliage fed freely upon the leaves soon after they were 
placed in the cage, whereas those placed in the cage containing the 
sprayed foliage did but little feeding during the first 3 days. During 
the next 3 days there was evidence of an increased amount of feeding. 
At the end of the 6 days, 25 of the beetles feeding on the sprayed 
foliage had died as against 6 dead beetles out of the 50 feeding on the 
unsprayed foliage. At this date (July 19) the experiment terminated 
on account of the withering of the sprayed foliage, and the impossi- 
bility of obtaining additional recently sprayed foliage. 

Another cage experiment to observe the feeding of beetles upon 
poisoned and unpoisoned foliage was undertaken during the summer of 

1909. This experiment was made upon young grapevines growing in 
large flower pots and covered with a wire screen (see fig. 22). Thus 
the freshness of foliage was assured throughout the experiment and 
the limited area of the plant permitted close observation of what took 
place. Three plants growing in pots were used in this experiment. 
The plants in two of the pots were sprayed very thoroughly, care being 
taken to cover the entire upper surface of all of the leaves with a poi- 
soned spray, which consisted of Bordeaux mixture with 3 pounds 
arsenate of lead to 50 gallons of the mixture, the proportions used in 
field experiments. The plant in the third pot was unsprayed. An 



REMEDIAL MEASURES. 



65 



additional object of this experiment was to observe the readiness with 
which beetles that had just emerged from the soil and had not had a 
previous opportunity of feeding on unsprayed foliage would feed on 
poisoned foliage as compared with beetles which were taken from 
vineyards and which had fed to some extent upon unsprayed vines. 
Accordingly 30 beetles, on emerging July 8, from soil inclosed with 
wire screens, were placed on a sprayed plant in pot I. Thirty more 
beetles collected in a vineyard, June 30, and fed on unsprayed leaves 
until July 8, were placed (July 8) in pot II, also containing a sprayed 
plant. At the same date 15 beetles which had just emerged were 
placed on an unsprayed plant in pot III. 

Table XXIV shows the death rate of the beetles in these three 



cages. 



Table XXIV 



-Experiments with poison sprays against grape root-worm beetles feeding 
on vines in confinement at North East, Pa., in 1909. 



Pot I. 


Pot II. 


Pot III. 


30 beetles emerged 
from soil July 8, 
and at once re- 
in o v e d to 
sprayed vine. 


30 beetles taken on 
vines in the field 
June 30 and 
placed on 
sprayed vine 
July 8. 


15 beetles emerged 

from soil July 8, 
and removed at 
once to un- 
sprayed vine. 


Number 
of dead 
beetles. 


Date. 


Number 
of dead 
beetles. 


Date. 


Number 
of dead 
beetles. 


Date. 


16 
12 

2 


July 9 
July 10 
July 11 


3 
10 
13 

2 

i 
l 


July 9 
July 10 
July 11 
July 12 
July 13 
July 17 


1 
1 

1 
1 
7 
3 
1 


July 15 
July 27 
July 29 
July 31 
Aug. 14 
Aug. 15 
Aug.28 ] 


30 




30 




15 


Total. J 







It was observed that the beetles just emerged from the soil and 
which had been placed in pot I without having had an opportunity 
to come in contact with unsprayed foliage fed as readily and indis- 
criminately on the poisoned leaves as did those placed on the unsprayed 
plant in pot III. The beetles placed on the other sprayed plant in 
pot II, which had had 8 or 10 days of feeding on unsprayed leaves, 
fed less upon the sprayed foliage, especially for the first 24 hours. A 
glance at the table will show that 50 per cent of the beetles in pot I 
died in 24 hours as against 10 per cent in pot II. On the fourth day 
all beetles in pot I had died and also 85 per cent of those in pot II, 
whereas it was not until the eighth day of the experiment that the 
first dead beetle was found in pot III, and 73 per cent of the beetles 
remained alive on this plant for more than a month. 
51282°— Bull. 89—10 5 



66 



THE GEAPE ROOT-WORM. 



FIELD EXPERIMENTS WITH POISON SPRAYS AGAINST THE 

BEETLES. 

The most striking evidence of the value of a poison spray as a 
direct killing agent of the beetles, however, was obtained by us in a 
field experiment conducted at North East, Pa., June 30, 1909. At 
this date our attention was called by Mr. Frank Pierce to the presence 
of large numbers of grape root-worm beetles feeding upon a block 
of several acres of vines planted that spring. These vines had been 
planted on land from which the vines of the greater portion of an 
unproductive vineyard had been removed early the same spring. 
The owner, not being aware at the time that these vines had been 




Fig. 29. — Young grapevine, unsprayed, showing extensive feeding by beetles of the grape root- 
worm. North East, Pa., 1909. (Compare with fig. 30.) (Original.) 

rendered unproductive by infestation by the grape root-worm, 
decided to replant the area immediately with young vines. After 
removing the old vines the ground was plowed and planted to the 
young vines and the space between these vines was sown to peas. 
Thus the soil was left uncultivated during the period between early 
May, when the peas were sown, and July 1 . Consequently the root- 
worm larvae which had infested the roots of the old vines were per- 
mitted to perform their transformations undisturbed. On June 28, 
when Mr. Pierce harvested the peas growing between the rows of 
grapevines, he observed some grape root-worm beetles feeding upon 



REMEDIAL MEASURES. 67 

foliage of the young vines. By June 30, when our attention was called 
to the infestation, the leaves of many of the plants were badly riddled 
by the beetles (see fig. 29) . At our suggestion Mr. Pierce sprayed part 
of these young vines quite thoroughly, using Bordeaux mixture and 
3 pounds arsenate of lead to 50 gallons of the mixture. This applica- 
tion was made with a hand spray pump mounted on a grape wagon, 
and the spray was directed at the plants by a man following behind 
the wagon and carrying an extension rod with two nozzles at the end 
and connected with the spray pump by a long lead of hose. In this 
way 4 rows of vines could be treated from the wagon. The vines 
were sprayed on the afternoon of June 30. It should also be stated 
that the portion of the old vineyard not removed in the spring and 
adjoining the young vines was treated at the same time. On the 
afternoon of July 1 an examination was made of the effect of the 
treatment of the previous day. Only a few beetles were found on the 
young vines as compared with the large numbers present previous to 
the application of the poison spray. Close examination of the soil 
beneath the vines disclosed the presence of a large number of dead 
beetles. Eighteen dead beetles were found beneath one vine, and 
under a number of others from 3 to 10 dead beetles were found. In 
addition to this we observed that a small brown ant was very actively 
removing evidence of the direct effect of the poison by tearing to 
pieces the dead beetles and often dragging away the whole body of 
the beetle. Wing-covers, heads, and legs of several beetles were to be 
seen beneath a single vine, and in several cases ants were observed to 
attack the beetles before they were quite dead. 

A visit was also made to the old trellised vines adjoining them, 
anticipating evidence of a wholesale migration of beetles from the 
young vines to the denser foliage of the old vines. Such, however, 
was not the case; although there was evidence of considerable feed- 
ing at an earlier date, few beetles were now observed on the vines. 
Several dead beetles were found beneath these old vines, and frag- 
ments of beetles and their wing-covers were also observed. A few 
days later a second application of Bordeaux mixture and arsenate 
of lead was made on these vines to take care of later emerging beetles. 
On a visit to these young vines July 10 not more than 4 live beetles 
were observed, although more than an hour was spent in the block, 
and not a single dead beetle was found on the ground beneath the 
vines, although fragments of their bodies were in evidence. If this 
timely application of a poison spray had not been made, the young 
vines would have been seriously injured by the feeding of the bee- 
tles; for it not infrequently happens that the beetles, where they 
are numerous and the foliage limited, as in this case, riddle the 
foliage and tear it into shreds until it has the appearance of being 
singed by fire. 



68 THE GRAPE ROOT-WORM. 

In view of the results described above, there can be no doubt as 
to the value of a poison as a direct and effective killing agent of the 
beetles in the open field. It is quite possible, moreover, that the 
rapid removal of dead bodies by ants and other agencies and the 
close search required to find them on account of the fact that their 
color is the same as that of the soil, and also by the fact that they 
were distributed over a large area on the foliage of full-grown vines, 
have resulted in the failure of other workers to find a sufficient num- 
ber of dead bodies of beetles in sprayed vineyards to warrant them 
in feeling that this method of control is as effective as might be 
desired. 

COMPARATIVE EFFECTIVENESS OF ARSENATE OF LEAD AND 

ARSENITE OF LIME. 

In our field work with arsenical sprays, planned for a period of 
two or three seasons, arsenate of lead was the insecticide used 
throughout the experiments. Since, however, many vineyardists 
were using arsenite of lime when this investigation commenced, it 
was deemed advisable to make a test of its efficiency as an insecti- 
cide against the grape root-worm beetle as compared with arsenate 
of lead. 

In the summer of 1907 a test of these two insecticides was made 
in two vineyards in different parts of the township of North East. 
One vineyard of about 8 acres belonging to Mr. W. S. Wheeler was 
divided into three plats. Two plats of about 3 acres each were 
sprayed, one with Bordeaux mixture and arsenate of lead and the 
other with Bordeaux mixture and arsenite of lime. The third plat 
of about 2 acres running through the middle of the block was left 
unsprayed. Two spray applications were made on these plats at 
the same dates, July 9 and July 27, with a gasoline-engine power 
sprayer (PI. X, fig. 2). The spray was applied at a pressure of about 
100 pounds, and about 100 gallons of the liquid were used per acre. 
The formula used on the plat sprayed with arsenite of lime was, 
copper sulphate, 5 pounds; lime, 6 pounds; resin-fishoil soap, 2 
pounds, and 1 quart arsenite of lime made according to Kedzie's 
formula (containing 4 ounces of white arsenic) to 50 gallons of water. 
The resin-fishoil soap was added to increase the mixture's property 
of adhering to the foliage. The formula used on the plat sprayed 
with arsenate of lead was, copper sulphate, 5 pounds; lime, 5 pounds; 
arsenate of lead, 3 pounds; and water, 50 gallons. The effect of these 
treatments in preventing egg deposition is shown by a count of the 
egg clusters on 25 vines in each of the three plats. It should be 
stated in addition that at the time of making the count of egg depo- 
sition there was evidence of a great deal more feeding by beetles on 
the foliage on the plat treated with arsenite of lime than upon the 



REMEDIAL MEASURES. 



foliage of the plat sprayed with arsenate of lead. (For 
Table XXV.) ' 



69 

results, see 



Table XXV. — Relative value of ar senile of lime and arsenate of lead as insecticides, as 
shown by egg depositions at North East, Pa., 1907. 



VINEYARD OF W. S. WHEELER. 



Date of 
appli- 
cation. 


Formula. 


Siz 
Large. 


3 of clus 

Me- 
dium. 


ters. 
Small. 


Total 
clus- 
ters. 


Esti- 
mated 
num- 
ber of 
eggs. 


Num- 
ber of 
vines. 


Num- 
ber of 
canes. 


Eggs 
per 
vine. 


Eggs 

per 

cane. 


Date 

exam- 
ined. 


1907. 
July 8 
July 27 


Unsprayed 

5-6-2-50+1 quart 

Kedzie 

5-5-3-50 


37 

27 
3 


102 

98 
14 


LSI 

132 
47 


290 

257 

li4 


6, 420 

5,610 

1,040 


2g 

25 
25 


50 

65 
51 


256. 8 

224. 4 
41.6 


128.4 

86.3 
20.39 


Aug. 14 

Do. 
Do. 



VINEYARD OF W. E. GRAY. 



July 6 
July 25 



July 6 
July 25 



Unsprayed 

Prepared Bor- 
deaux: 1 qt. 
arsenite lime, 
2 qts. fishoil 
soap, 50 gals. 
water 

Prepared Bor- 
deaux: 3 II is. 
arsenate of 
lead, 50 gals, 
water 



28 


119 


139 


286 


6,360 


25 


75 


2.54. 4 


84.8 


21 


107 


155 


2S3 


5,810 


2.'. 


63 


232.4 


92.22 


• 11 


49 


78 


136 


2,800 


25 


58 


112.0 


48.27 



The vines on all these plats were quite thrifty and were carrying 
a heavy foliage. 

The second experiment for comparing the value of these two poi- 
sons against the grape root- worm beetle was made on a 12-acre vine- 
yard belonging to Mr. W. E. Gray, North East, Pa. The vineyard 
was divided into three plats, 5 acres on the east side, 2 acres 
through the middle of the block, and 5 acres on the west side. In 
this experiment a commercial brand of prepared Bordeaux mixture 
was used. The poison ingredients of the spray, however, were the 
same as in the experiments on the vineyard of Mr. Wheeler. The 
plat on the east side of the vineyard was sprayed with a mixture of 
2 gallons prepared Bordeaux mixture, 1 quart of arsenite of lime, 
Kedzie formula, 2 quarts of fishoil soap, and 50 gallons of water. 
The plat on the east side of the vineyard was sprayed with a mixture 
of 2 gallons of prepared Bordeaux mixture, 3 pounds of arsenate of 
lead, and 50 gallons of water. The 2 acres through the middle of 
the vineyard were left unsprayed. As in all of our other spray exper- 
iments, the foliage in the untreated plat showed much more feed- 
ing by the beetles at the time of taking the records of egg deposition. 
A greater amount of feeding by the beetles was also apparent on the 
foliage treated with arsenite of lime than upon that treated with 
arsenate of lead. The results of these experiments are set forth in 



70 THE GEAPE BOOT-WOBM. 

Table XXV and indicate a much greater efficiency from the arsenate 
of lead application than from the application of arsenite of lime. 

Vineyardists throughout Erie County have practically abandoned 
the use of arsenite of lime as a poison spray against the grape root- 
worm beetle, and arsenate of lead is now used almost exclusively. 

RESULTS OF VINEYARD EXPERIMENTS WITH POISON SPRAYS. 

The field experiments of this investigation were carried on during 
the three consecutive seasons of 1907, 1908, and 1909, and in view 
of results obtained by spraying by the senior author during his single 
season of cooperative work with the late Prof. M. V. Slingerland 
the remedial measures tried out were almost entirely along the line 
of spray applications, it being his belief that the most effective results 
could be obtained by this method of combat. Some of the principal 
points upon which information was desired were the effect of poison 
sprays in ridding the vines of the grape root- worm beetles, the effect 
of this application in preventing egg deposition by beetles, the rela- 
tive effect of this treatment on vines of different ages and different 
stages of infestation, the determination of the immediate seasonal 
benefit to the vines by prevention of egg deposition, and the cumu- 
lative benefit both in vigor of vines and crop yield obtained by 
following up a line of treatment for several consecutive seasons. 

A brief survey of vineyard conditions in the townships of North 
East, Pa., during the late summer of 1906 enabled us to make a 
selection of vineyard areas in the various stages of infestation and 
decline best suited to the working out of these problems. A block 
of vineyard owned by Mr. Roscoe Davidson, of North East, was 
selected for the experiment to determine the effect of poison appli- 
cations. The conditions existing in this vineyard were well suited 
to the plan of experiment. The area was about 12 acres, thus mak- 
ing it possible to secure results of commercial value. The vineyard 
(PI. VI) is situated on a northern slope and is divided into four 
blocks or sections. The soil is of a loose gravelly texture. The 
lower northern section consists of young Concord vines about 7 
years planted, the two sections immediately above are made up of 
vines about 20 years planted and are referred to as old Concords, and 
the south section consists of a block of 7-year-old Niagara vines 
referred to in these experiments as young Niagaras. At the time 
the experiment was undertaken the whole block showed a uniformly 
heavy infestation of larvae on the roots of the vines. With the excep- 
tion of the section of young Concords, however, the vines had not 
yet reached the stage of serious decline and were still producing 
fairly profitable crops. With the young Concords the case was 
different. Our attention had been called to these vines late in the 
summer of 1906 at the time when the fruit was commencing to color. 



Bui. 89, Bureau of Entomology, U. S. Dept. of Agriculture. 



Plate VI. 




REMEDIAL MEASUEES. 71 

So serious was the injury of the larvae to the roots at this date that 
the large crop of fruit which some of these vines were carrying was 
actually shriveling up and dropping to the ground. By the fol- 
lowing spring many of these vines had either died outright or were 
in a very weakened condition. Plate IV, figure 2, gives an example 
of the manner in which the fibers had been removed from the roots 
of many of these young vines by the larva? of the root- worm, and 
shows the limited growth of new canes as a result of the infestation 
which rendered the vine incapable of producing a crop of fruit during 
the coming season. Thus the variety of conditions existing in this 
vineyard was such as to enable us to work out several features of 
the problem on the same block, namely, the effect of a poison-spray 
application on vines of different varieties, of different ages, and in 
different stages of injury, all growing side by side under practically 
the same conditions. All of the vineyard was subjected to the 
same treatment in regard to cultivating, fertilizing, and spraying, 
with the exception of six rows running through the center of the 
block (PI. VI) which cut through all four of the sections mentioned 
above. These six rows were reserved as a check and from these 
the spraying alone was withheld. 

Below are given all of the data relating to the experiment conducted 
on this vineyard during the seasons of 1907, 1908, and 1909, together 
with the results obtained. 

As the time for the emergence of the beetles from the soil drew 
near daily visits were made to this vineyard during the latter end 
of June and early July, 1907. On July 15 an occasional beetle was 
found feeding on foliage near the ground. All preparations had 
been made for spraying as soon as the first beetles appeared, and 
the first application was made at this date. The sprayer used was 
a gasoline-engine power outfit constructed especially for vineyard 
work (PL X, fig. 2). The regular Bordeaux formula, 5-5-50, was 
used, and to this 3 pounds of arsenate of lead were added, this latter 
ingredient being the active poison agent of the spray. A pressure 
of about 100 pounds was maintained throughout the application, 
and about 100 gallons of spray mixture were applied per acre. Fixed 
nozzles were used of the eddy chamber type. 

On July 23 a second application was made, the same formula 
being used and the same pressure maintained. 

During the season of 1908-9 the same spray formula, machinery, 
and nozzle arrangement were used and the same pressure main- 
tained. The only varying factor was the dates of application, which 
varied each season with the date of emergence of the beetles. To 
facilitate comparison, the dates of application, effect of spray on 
egg deposition, prevalence of larvae at roots, and crop yield as com- 
pared with the unspraved check are tabulated for the three seasons. 
(Tables XXVI, XXVII, and XXVIII.) 



72 



THE GRAPE ROOT-WORM. 



Table XXVI. — Effect of poison spray against the grape root-worm as shown by relative 
occurrence of eggs in sprayed and unsprayed plats in Davidson vineyard for 1907, 1908, 
and 1909, North East, Pa. 

CHECK (UNSPRAYED) PLAT— YOUNG CONCORD VINES. 



Date of 
applica- 
tion. 


When 
examined. 


Number of egg clusters found. 


Estimated 
number 
of eggs. 


Num- 
ber of 
vines. 


Num- 
ber of 
canes. 


Average num- 
ber of eggs. 


Large. 


Me- 
dium. 


Small. 


Total. 


Per 
vine. 


Per 
cane. 




Aug. 2. 1907 
July 13,1908 
July 19,1909 


92 

31 
41 


163 
109 

41 


246 
190 
74 


501 
330 
156 


11,950 
6,720 
4,020 


25 
25 
25 


55 
29 
35 


478 

268.8 

160.8 


217.2 
231.7 
114.8 



SPRAYED PLAT— YOUNG CONCORD VINES. 
Formula: 5 lbs. blue vitriol (copper sulphate), 5 lbs. lime, 3 lbs. arsenate of lead, 50 gallons water. 



July 
July 


15 !l 


2, 1907 




7 


10 


22 


39 


870 


25 


66 


34.8 


13.8 


June 
June 


22 U , 

so ) Ju 'y 


13, 1908 







5 


16 


21 


310 


25 


41 


12.4 


7.5 


July 
July 


14 :Hy 


19, 1909 




1 


7 


12 


20 


380 


25 


47 


15.2 


8.8 






CHECK 


(UNSPRAYED) PLAT— OLD CONCORD VINES. 










Aug. 


2, 1907 




52 


136 


213 


401 


8,810 


25 


69 


352.4 


127.6 






Julv 


13, 1908 




47 


139 


146 


332 


7,980 


25 


71 


319.2 


112.3 






July 


19, 1909 




35 


57 


91 


183 


4,370 


25 


68 


174.8 


64.2 



SPRAYED PLAT— OLD CONCORD VINES. 
Formula same as above (5-5-3-50). 



a bU* ^ 


4 


13 


13 


30 


720 


25 


72 


28.8 


10.0 


June" iVuly 13,1908 


2 


13 


10 


25 


590 


25 


64 


23.6 


9.2 


July 14 } Jl,ly 19 > 1909 





7 


7 


14 


280 


25 


81 


11.2 


3.4 



CHECK (UNSPRAYED) PLAT— YOUNG NIAGARA VINES. 



Aug. 6, 1907 
July 15,1908 
July 19,1909 



183 
60 
27 



4,590 

1,400 

570 



183.6 
56.0 
9.6 



93.6 
41.4 

4.7 



SPRAYED PLAT— YOUNG NIAGARA VINES. 
Formula same as above (5-5-3-50). 



July 15 

July 23 

June 22 

June 30 

July 2 

July 14 



JAug. 6, 1907 





2 


1 


3 


jjuly 15,1908 





1 





1 


jjuly 19,1909 


1 


4 


7 


12 



70 


25 


35 


2.8 


30 


25 


36 


1.2 


240 


25 


51 


9.6 



2.0 

.69 

4.7 



REMEDIAL MEASURES. 



73 



Table XXVII. — Effect of poison .spray against the grape root-worm as shown by occur- 
rence of larvse at roots of vines in sprayed and unsprayed plats in Davidson vineyard 
in 1907, 1908, and 1909, at North East, Pa. 

DIGGINGS MADE IN SUMMER OF 1907. 



Date of examination. 


Number 
of vines. 


Variety and age of 
vines. 


Number of larvae. 


Un- 
sprayed 
plat. 


Sprayed 
plat.' 


September 5, 1907 . . . 


1 
1 

1 


Young Concord . . . 

Old Concord 

Young Niagara 


92 
91 

(i 


6 
1 



Do 


Do... 





DIGGINGS MADE IN SUMMER OF 1908. 



August 26, 1908 


10 
5 
5 


Young Concord.. . 

Old Concord 

Young Niagara 


214 
86 

58 


40 
4 
5 


August 25, 1908 


Do 



DIGGINGS MADE IN SUMMER OF 1909. 



September 8-9, 1909 

September 10-15, 1909 


5 
5 
5 


Young Concord. . . 

Old Concord 

Young Niagara 


39 
13 1 
17 


September 11-15, 1909.. 





Table XXVIII. — Davidson vineyard. Effect of spray applications on the crop yield 
for the seasons 1908 and 1909 at North East, Pa. 



FOR SEASON OF 1908. 



Year. 


Variety and age of 
vines. 


Treatment. 


Plat 

area. 


Plat 
yield. 


Value per 
basket. 


Value per 

acre. 


Spray 

benefit 
per acre. 


1908 
1908 
1908 
1908 
1908 
1908 


Young Concord.. 
do 

Old Concord 

do 

Young Niagara 

do 


Spraved 

Unsprayed 

Spraved 

Unsprayed 

Spraved 

Unsprayed 


Acre. 

X 


Lb.baskets 
101.8 
81.8 
502. 
455.0 
231.4 
150.4 


Cents. 
13 
13 
13 
13 
9 
9 


$26. 26 
21.06 
86. 97 
78.91 
62. 37 
40.50 


$5. 20 


8. 06 


21.87 







FOR SEASON OF 1909. 



1909 
1909 
1909 
1909 
1909 
1909 



Young Concord. 

....do 

Old Concord.... 

....do 

Young Niagara. 
....do 



Sprayed 

Unsprayed.. 

Sprayed 

Unsprayed.. 

Sprayed 

Unsprayed.. 



i 


435.8 
217.0 
1,039.0 
836. 
158. 2 
85.0 


11 
11 
11 
11 
28 
28 


$95. 70 
47.74 
152. 35 
112. 65 
132. 72 
71.40 


$47. 96 


39.70 


61.32 





The effect of the spray on egg deposition was obtained by stripping 
all of the loose bark from 25 consecutive vines in the sprayed portion 
and also in the check rows, making an actual count of the number of 
egg clusters deposited on an equal number of consecutive vines in the 
sprayed and unsprayed plats. This has proved to be one of the best 
ways to determine the immediate direct effect of spray applications. 
These examinations were made at a time, determined by careful 



74 THE GRAPE ROOT- WORM. 

observation, when the maximum number of eggs had been deposited, 
and before but few larvae had hatched from the earliest deposited 
eggs. 

All of the bark was carefully stripped from the vine and a count 
made of the egg clusters found. The number of eggs in these clusters 
may vary from 3 or 4 to 75 or even 100. Since it was impossible to 
make an actual count of the individual eggs, the clusters were classi- 
fied, as the count was made during the examination of the vines, as 
large when they contained approximately 50 eggs or more, medium 
when they contained about 30 eggs, and small when they contained 
about 10 eggs. In this manner we obtained the estimated number of 
eggs per vine given in the Table XXVI dealing with egg deposition. 
A simple enumeration of the number of egg clusters deposited per 
vine regardless of the number of eggs which they contained would 
have given but an inadequate idea of the total number of larvae which 
might infest the roots of these vines. The number of canes per vine 
is also given to indicate the size of the vine, since the limit of the area 
upon which the beetles could deposit eggs would have some influence 
on the number of clusters deposited. 

The prevalence of larvae at the roots of vines in sprayed and 
unsprayed plats was determined by making careful diggings at the 
roots of a given number of vines in both the sprayed and the 
unsprayed plats (Table XXVII). During these diggings the differ- 
ence in the number of root fibers thrown out by vines in the sprayed 
and unsprayed plats was very noticeable. On May 13, 1908, after 
the vineyard had received the protection of one season's treatment 
with poison spray the root systems of several vines were examined 
in the block of young Concords. It was found that the roots of 
many of the vines in the unsprayed plat were almost entirely devoid 
of new root fibers, and that the large roots were badly channeled and 
pitted by the feeding of the larvae of the grape root-worm, whereas 
the roots of vines examined in the sprayed portion of this vineyard 
showed that they had thrown out large masses of new fibrous roots 
during the growing season as a result of the protection the spraying 
had afforded them in the prevention of the deposition of eggs by the 
beetles. Plate IV, figure 1, will illustrate this luxuriant growth of 
new root fibers on roots of sprayed treated vines, practically all of 
which were produced during the growing season of 1907, as compared 
with the lack of them on the unsprayed vines (PI. IV, fig. 2). These 
illustrations also indicate the recuperative power of badly injured 
grape vines when protection from the larvae is afforded; for in the 
spring of 1907, previous to the protection of the vines by the poison 
spray, the roots of the vines in the sprayed plat were as devoid of 
root fibers as were those in the unsprayed plat, as was shown by dig- 
gings made in the spring of 1907. 



Bui. 89, Bureau of Entomology, U. S. Dept. of Agriculture. 



Plate VII. 




Fig. 1. — Retarded growth of vines in the unsprayed plat. (Original.) 




Fig. 2.— Vigorous growth of vines in the sprayed plat. (Original.) 



Views of Experimental Plats in Mr. Roscoe Davidson's Vineyard at North 

East, Pa. 



REMEDIAL MEASURES. 75 

In addition to the above-described methods of comparing the effect 
of the treatment of this vineyard with a poison spray, an accurate 
count of the number of baskets of grapes picked from equal areas in 
the sprayed and unsprayed plats was made and their cash value for 
each season recorded. This data, covering the seasons 1907, 1908, 
and 1909, is presented in Table XXVIII. 

Plate VII, figure 1, shows the light growth of the vines in the 
unsprayed plat as compared with Plate VII, figure 2, showing the 
heavy growth in the sprayed plat after three years' treatment. 

RESULTS OF VINEYARD RENOVATION EXPERIMENTS. 

At the time this investigation was commenced the feeling was 
quite common among vineyardists of North East, Pa., that it would 
be useless to attempt to restore to their former productivity some of 
the vineyards very badly injured by the root-worm, and that it would 
be cheaper to tear out these old vines and replant the ground to 
new vines. In view of the fact that our survey had shown that 
many young vineyards just coming into bearing were also declining 
very rapidly under attacks of the pest, and that a run-down condition 
of old vines was very common throughout the entire grape belt, it 
was deemed desirable to investigate as to what could be done in the 
way of renovating a badly run-down vineyard. 

RENOVATION EXPERIMENT ON AN OLD VINEYARD. 

During the fall of 1906 our attention had been called to the condi- 
tion of 10 acres of old vineyard which in previous years had possessed 
the reputation of being very productive but had suddenly shown a 
rapid decrease in yield and also in growth of vine. The yield of this 
vineyard, which in 1905 was 6,597.5 pounds of fruit per acre, declined 
in 1906 to 1,697 pounds per acre, showing a decrease of 4,900.5 
pounds and barely covering operating expenses. When visited by us 
in the fall of 1906 the foliage of these vines was found to be riddled 
by the beetles of the grape root-worm, the cane growth was stunted, 
and many vines simply threw out tufts of puny shoots near the lower 
wire of the trellis. The roots were almost devoid of fibers and badly 
scarred by the feeding of grape root-worm larvae, and the fruit hung 
in scraggy clusters of undersized berries — in short, this vineyard had 
all the appearance of being in the last stages of production as a result 
of grape root- worm injury. In the spring of 1907 it was decided to 
undertake an experiment in this vineyard to determine if by ridding 
the vines of this pest, the vineyard could be restored to its former 
condition of profitable production. At this point it should be stated 
that the vineyard had received in previous years only indifferent 
cultivation and practically no fertilizing or spraying. The importance 



76 THE GRAPE ROOT-WORM. 

of these operations was recognized at the outset of the experiment and 
arrangements were made to give the vines thorough cultivation and 
liberal fertilizing in addition to thorough spraying with a poison and 
a fungicide; in fact, to treat the vineyard according to the most 
approved methods of vineyard management. 

That spring when the vineyard was pruned many of the badly 
weakened vines were cut back to the ground and others to the lower 
wire of the trellis. Even on the most vigorous vines, not more than 
one to three fruit-bearing canes were left, it being thought desirable 
to concentrate the remaining energies of the weakened vines and 
force the vegetative growth rather than attempt to produce fruit of 
an inferior quality such as was borne by the vines during the season 
of 1906. In order that some light might be thrown on the effect of 
different kinds and amounts of fertilizer used in restoring these 
injured vines it was decided to divide the vineyard into seven plats 
of one acre each and the following kinds and amounts of fertilizer 
were applied : 

Plat I. Barnyard manure, 7 wagon loads. 

Plat II. Complete high grade commercial fertilizer, 1,000 pounds. 
Plat III. Complete high grade commercial fertilizer, 1,000 pounds plus 100 pounds 
sodium nitrate. 

Plat IV. Sodium nitrate, 400 pounds. 
Plat V. High grade commercial fertilizer, 1,000 pounds. 
Plat VI. High grade commercial fertilizer, 500 pounds. 
Plat VII. No fertilizer; no spraying. 

The brand of fertilizer used in 1907-8 analyzed available phos- 
phoric acid, 11.28 per cent; potash, 5.89 per cent; nitrogen, 3.41 
per cent. In 1909 a brand of fertilizer was used analyzing phos- 
phoric acid, 8 per cent; potash, 8 per cent; nitrogen, 5 per cent. 
The plats commenced on the west side of the vineyard and ran east- 
ward. Plats I, V, VI, and VII included seven rows measuring 
approximately one acre in area. Plats II, III, and IV contained 14 
rows each, but all the data here given are reduced to a 7-row or 1-acre 
basis for convenience in comparison. The ground on which this 
vineyard is planted is quite level and is of a stony loam on the west 
side grading to an almost stoneless clay on the east side where it 
has been somewhat enriched by wash from a slight elevation lying 
immediately south, which doubtless is responsible for the greater 
productivity of plats 5, 6, and 7, at the beginning of the experiment. 

The barnyard manure was spread broadcast over the rows of Plat 
I during the month of April. The commercial fertilizer was dis- 
tributed on the other plats in two equal applications, the first being 
made May 21, when active growth of the vines commenced. The 
second application was made June 18, about one month later. 

All of the fertilizer was applied with a broadcast fertilizer dis- 
tributor and immediately followed by a spring-tooth cultivator. 



REMEDIAL MEASUEES. 



77 



The ground was plowed early in May and received three thorough 
cultivations during the summer. It should be observed at this 
point that this is by no means an attempt to solve the problem of 
vineyard fertilization, which belongs to the province of the horticul- 
turist, and that the results obtained on these plats are presented 
without comment upon this feature of the experiment, leaving the 
reader to draw his own conclusions. 

With the appearance of the first beetles all of the plats except the 
check plat received a thorough spraying with Bordeaux mixture and 
arsenate of lead, using the following formula: Copper sulphate, 4 
pounds; quicklime, 4 pounds; arsenate of lead, 3 pounds. A 
second spraying with the same ingredients was made ten days to 
two weeks later. (See exact dates on Table XXIX, showing egg 
deposition.) 



Table XXIX. — Effect of poison spray against the grape root-worm as shown by relative 
occurrence of eggs on sprayed and unsprayed plats of the Porter vineyard during 1907, 
1908, and 1909, at North East, Pa. 



IXSPRAYED PLAT. 



Year 


When exam- 
ined. 


Number of egg clusters found. 


Esti- 
mated 
num- 
ber 
of eggs. 


Num- 
ber 
of 

vines. 


Num- 
ber 
of 

canes. 


Average num- 
ber of eggs. 


Date of 

spray 


Large. 


Medi- 
um. 


Small. 


Total. 


Per 

vine. 


Per 

cane. 


applica- 
tion. 


1907.. 


Aug. 12,1907 
Julv 22,1908 
July 21,1909 


97 
45 
37 


150 
91 
5f> 


238 
78 
94 


485 
214 
187 


11,730 
5, 700 
4,470 


25 
25 
25 


76 
76 
97 


469.2 
230. 4 
178. 8 


154. 37 
78.9 
46.08 




1908.. 
1909. . 









SPRAYED PLAT. 
Formula: 4 lbs. blue vitriol (copper sulphate), 4 lbs. lime, 3 lbs. arsenate of lead, 50 gallons water. 



1907. 
1908. 
1909. 



Aug. 13,1907 


1 


21 


34 


56 


1,440 


25 


50 


57. 


25.7 


July 22,1908 





10 


4 


14 


340 


25 


58 


13.6 


5.8 


July 21,1909 


3 


8 


7 


18 


460 


25 


117 


18.4 


3.9 



/Julv 13 

\Julv 22 

(June 24 

\July 2 

/July 5 

\July 16 



The spray applications were made with a gasoline-engine spraying 
outfit specially mounted for vineyard work (PI. X, fig. 2) having an 
arrangement of fixed nozzles, three on each side, the two lower of 
which throw the spray on the side of the vines as the machine passes 
through the rows. The upper nozzle reaches out over the top of the 
row throwing the spray downward so that it covers the new growth 
at the top of the trellis. This downward direction of the spray to 
cover the new growth at the top of the trellis is highly desirable since 
the beetles exhibit a tendency to feed more freely on this new growth, 
especially after the lower leaves have been coated with a poison spray. 
A pressure of from 100 to 125 pounds was maintained throughout 



78 



THE GRAPE ROOT-WORM. 



the operation, using about 100 gallons of spray liquid per acre. With 
this spraying outfit it is possible to cover from 8 to 10 acres of vine- 
yard per da} 7 . 

METHODS OF OBTAINING AND RECORDING RESULTS. 

As in the preceding field experiment, the results of the spray appli- 
cation were determined by counting the number of egg clusters 
deposited on the vines by the grape root-worm beetles at a time when 
the maximum number of eggs were to be found upon the vines. All 
of the bark was removed from 25 consecutive vines in the unsprayed 
plat and also in the adjoining sprayed plat. The results of these 
examinations are given in Table XXIX for the three seasons 1907, 
1908, and 1909. Table XXX indicates the effect on the larvae of 
spraying as shown by the number of larvae found at the roots of the 
vines by carefully removing the soil from the base of the vine for a 
distance of 3 or 4 feet from the trunk of the vine and to a depth of a 
foot or 16 inches, going several inches below the second whorl of roots. 

Table XXX. — Effect of poison spray against the grape root-worm as shown by relative 
occurrence of larvx at roots of vines in sprayed and unsprayed plats of Porter vineyard, 
at North East, Pa., in 1907, 1908, and 1909. 



Date of examination. 


Number 
of vines. 


Variety and afje of 
vines. 


Number of larvae. 


Un- 
sprayed 
plat . 


Sprayed 

plat. 


April and May 


40 

5 
10 
12 

5 


20-year Concord . . . 

do 

.. do . 


76 
92 

100 
67 

115 




September 25, 1907 




May 27-28, 1908 


21 
7 
19 


June 19, 1909 


...do... 


September 25, 1909 


do 







When the crop was ready to harvest, the final effect of the season's 
treatment was obtained for each plat. Table XXXI indicates the 
plat number, area, fertilizer applied, number of crates or baskets of 
grapes, net weight of fruit, value per pound or basket, cash value per 
acre, cost of spraying and fertilizing, and value of crop less cost of 
treatment. 

The data in Table XXXI, giving the results of the treatment from 
1907 to 1909, inclusive, show a great increase in crop yield of this 
vineyard as a result of thorough spraying and heavy fertilization. 
This experiment proves conclusively that if energetic measures are 
taken with vineyards rendered practically unprofitable as a result of 
grape root- worm injury they may be made to yield very profitable 
crops. 



REMEDIAL MEASURES. 



79 



Table XXXI. — Crop yield of plats in renovation experiments for 1907, 1908, and 

1909, at North East, Pa. 

FOR SEASON OF 1907. 



Plat 
num- 
ber. 


Plat 
area. 


Kind of fertilizer used. 


Num- 
ber of 
8-pound 
baskets 
per 
acre. 


Net 
weight 
of fruit 

in 

pounds 

per 

acre. 


Aver- 
age 

value 
of fruit 

per 
8-pound 

basket 
for 1907, 

1908, 

1909. 


Value 

of fruit 

per 

acre. 


Cost 
of two 
spray- 
ing ap- 
plica- 
tions 
per 
acre. 


Cost 
of fer- 
tilizer 

and 
appli- 
cation 

per 

acre. 


Value 
of fruit 

less 
cost of 
spray- 
ing and 
fertiliz- 
ing per 

acre. 


I 


Acre. 
1 
1 

1 

1 
1 

1 

1 




129 
198 

211 

194 
308 

255 

263 


968 
1,485 

1,590 

1.400 
2,310 

1,917 

1,975 


Cents. 

m 

124 

12J 

12J 

12J 
12J 


$16.11 
24. 75 

26.37 

24.25 
38.50 

31.87 

32.87 


$4.00 
4.00 

4.00 

4.00 
4.00 

4.00 


$22. 00 
18.50 

21.00 

10.50 
18.50 

9.50 


-89. 89 


II 
III 

IV 
V 

VI 

VII 


Commercial fertilizer, 1,000 

pounds. 
Commercial fertilizer, 1,000 

pounds; sodium nitrate, 100 

pounds. 
Sodium nitrate, 400 pounds. . . 
Commercial fertilizer, 1,000 

pounds. 
Commercial fertilizer, 500 

pounds. 
No fertilizer; no spraying 


2.25 
1.37 

9.75 
16.00 

18.37 

32.87 











FOR SEASON OF 1908. 



I 
II 


Acre. 
1 
1 


III 


1 


IV 
V 


1 
1 


VI 


1 


VII 


1 



Barnyard manure 

Commercial fertilizer, 1,000 

pounds. 
Commercial fertilizer, 1,000 

pounds; sodium nitrate, 100 

pounds. 
Sodium nitrate, 400 pounds. . . 
Commercial fertilizer, 1,000 

pounds. 
Commercial fertilizer, 500 

pounds. 
No fertilizer; no spraying 



427 
482 


2,606 
2,921 


Cents. 
12| 
12! 


$53.37 
60.25 


$4.00 
4.00 


$22. 00 
18.50 


590 


3,542 


12! 


73.75 


4.00 


21.00 


649 
681 


3,912 
4,153 


12! 

12! 


81. 12 

85. 12 


4.00 
4.00 


10.50 
18. 50 


630 


4,022 


12! 


78.75 


4.00 


9.50 


535 


3,369 


12! 


66.87 











$27. 37 
37.75 



66. 62 

62.62 



65. 25 
66. 86 



FOR SEASON OF 1909. 



I 
II 


Acre. 
1 
1 


III 


1 


IV 
V 


1 
1 


VI 


1 


VII 


1 



Barnyard manure 

Commercial fertilizer, 1 ,000 

pounds. 
Commercial fertilizer, 1 ,000 

pounds; sodium nitrate, 100 

pounds. 
Sodium nitrate, 400 pounds. . . 
Commercial fertilizer, 1,000 

pounds. 
Commercial fertilizer, 500 

pounds. 
No fertilizer; no spraying 



1,188 

1,282 


9,049 
9,898 


Cents. 
12! 
12! 


$148. 50 
160.26 


$4.00 
4.00 


$22. 00 
18.50 


1,184 


9,146 


12! 


148.00 


4.00 


21.00 


1,037 
1,171 


8,372 
9,090 


12! 
12i 


129.62 
146. 37 


4.00 
4.00 


10.50 
18.50 


1,260 


9,580 


12! 


157.50 


4.00 


9.50 


855 


6,412 


12! 


106. 87 











$122. 50 
137. 76 



115. 12 
123. 87 



144. 00 
106. 87 



80 THE GEAPE ROOT-WOEM. 

In examining the yields for the various plats it will be observed 
that in the first year of the experiment plats I, II, III, and IV fell con- 
siderably below the unsprayed and unfertilized plat. This condition 
is due in a great measure to the fact that vines in plats V, VI, and VII 
were in a somewhat more thrifty condition at the outset of the experi- 
ment. The soil in these plats grades to a clay loam and has been 
enriched somewhat by the wash from an elevation immediately south 
of them. While the untreated plat shows great improvement in 
yield simply as a result of thorough cultivation, yet the annual 
increase in yield on this plat was much less than that upon the 
treated plats in the same soil. 

In addition to this increase in crop yield there was noted a great 
improvement in the quality of the fruit both in size of berries and of 
clusters. Plate IX, figure 2, gives a comparison of the size and com- 
pactness of fruit on a vine in the sprayed portion as compared with 
fruit on a vine in the unsprayed portion shown in Plate IX, figure 1. 

It was also found that the fruit in the sprayed plats remained firm 
and that there was practically no loss from shelling of the berries, 
whereas the fruit and stems in the unsprayed plat were badly mildewed 
and there was a great deal of shelling of berries. This benefit is 
derived from the fungicidal effect of the Bordeaux mixture. This 
increase in crop yield has also been accompanied by a marked improve- 
ment in the vigor of the vines throughout this vineyard. Practically 
all of the vines are now in a condition to produce a full crop of fruit, 
and there is no reason why this vineyard should not continue to 
produce as profitable crops as it did previous to its infestation, pro- 
vided it is subjected to treatment similar to that which it has received 
during this investigation. 

Plate VIII affords a comparison of the growth of vine at the 
beginning and at the end of the experiment, the upper figure show- 
ing the vineyard at the beginning of the experiment, and the lower 
figure after three years' treatment. 

RENOVATION EXPERIMENT ON A YOUNG VINEYARD. 

About the year 1900 there was a heavy planting of new vineyards 
throughout the Lake Erie grape belt. Scarcely had these young 
vines come into bearing when the owners noticed a rapid decline 
both in their crop yield and in vigor of vines. Close observation 
indicated that this decline was due largely to injury by the grape 
root-worm, and that the decline of these young vines was even more 
rapid than in the case of older, well-established vines. In many 
vineyards it was found that young vines had been killed outright in 
a single season. 



39, Bureau of Entomology, U. S. Dept. of Agricultuie. 



Plate VIII. 





Views of the Porter Experimental Vineyard, Showing Comparative Growth of 
the Vines in 1907 at the Beginning of the Experiment (Upper Figure), 
and in 1909 at the End of the Experiment (Lower Figure), North East, Pa. 
(Original.) 



Bui. 89, Bureau of Entomology, U. S. Dept of Agriculture. 



Plate IX. 




Pig. 1.— Average condition of berries in the untreated plat, North East, Pa., 1909. (Original.) 




Fig. 2.— Average condition of berries in the treated plats, North East, Pa., 1909. (Original.) 
Condition of Fruit on Vines in Plats of the Porter Experimental Vineyard. 



REMEDIAL MEASURES. 81 

During the summer of 1907 our attention was called to the condi- 
tion of a young vineyard near North East, Pa., belonging to Mr. H. E. 
Mosher, which for the first three years of bearing had maintained a 
very thrifty condition. The soil of this vineyard had been well 
cultivated and heavily fertilized with barnyard manure, yet in spite 
of this favorable treatment the crop yield in 1907 decreased to an 
alarming extent, amounting only to about one-eighth of the value of 
the yield for the previous season. 

This vineyard is about 5 acres in extent. The crop value in 1904, 
first year bearing, was $127.51; in 1905 it was $410.77; in 1906 it 
was $435.72, but in 1907 it was only $55.92 

There is every reason to believe that the grape root-worm was 
directly responsible for the sudden decline of these vines, for when 
the roots of many of the vines, which were practically dead, were 
examined by us they were found to be entirely devoid of fibrous 
roots, and the whiplike larger roots and the crowns of the vines were 
badly furrowed and scarred as a result of feeding by the full-grown 
larvae (PL III). From one section of this vineyard, about 2\ acres 
in area, containing 1,584 vines, 563 dead vines were removed in the 
spring of 1908. In addition to this, about 50 per cent of the remain- 
ing vines were cut back either to the ground or to the lower wire of 
the trellis, thus greatly limiting their fruit production for the coming 
season. So discouraged was the owner with the condition of this 
vineyard that he was at the point of pulling out all of the vines and 
replanting it anew. At our request, however, he permitted us to 
plan a renovation experiment on this section to determine if the vines 
could be restored to a thrifty condition and again produce profitable 
crops. This experiment was commenced in the spring of 1908. The 
remaining vines were severely cut back, as mentioned above, and new 
vines planted in the place of those which had been removed. The 
vines were heavily fertilized with a high-grade fertilizer. In this 
case, owing to the limited root area, as a result of the feeding bv the 
larva?, it was deemed desirable to sprinkle the fertilizer by hand 
about the base of the vines instead of scattering it broadcast over the 
whole area between the rows. Twelve rows received an application 
of 400 pounds of nitrate of soda and 24 rows received an application 
of high-grade commercial fertilizer at the rate of 2,000 pounds per 
acre. This fertilizer was distributed in two applications; the first on 
May 21, when active growth was well started, and the second about a 
month later. 

With the appearance of the first beetles, June 23, 1908, the vines 
were sprayed thoroughly with Bordeaux mixture and arsenate of 
lead, using 4 pounds of copper sulphate, 4 pounds of stone lime, and 3 
51282°— Bull. 89—10 6 



82 THE GRAPE ROOT-WORM. 

pounds of arsenate of lead to 50 gallons of water. On July 2, 1908, a 
second application was made, using the same formula as for the first 
application. The spray was applied with a traction sprayer at a 
pressure of about 100 pounds, and about 100 gallons of fluid were 
used per acre, covering the vines quite thoroughly with a fine spray. 
The whole 5 acres were included in each of these two spray applications. 
As a result of this treatment most of the vines made quite a vigorous 
growth of wood, which gave a good supply of bearing canes for next 
season. Owing to the severity with which these vines were cut back 
in the spring, the cash value of the crop from the 5 acres was $31.02. 

The treatment given this section of vineyard in 1908 was duplicated 
during the summer of 1909. The same amount of fertilizer was 
applied, and two applications of spray were made, the first applica- 
tion June 29, the second July 8. As a result of the second season's 
treatment the vines have taken on a healthy appearance and made a 
vigorous growth of new canes. The number of grape root-worm 
beetles has been reduced to a minimum, as shown by the small amount 
of feeding on the foliage and by the number of egg clusters deposited. 
An examination made on July 24 showed but nine egg clusters on 25 
sprayed vines as against 73 egg clusters on the same number of un- 
sprayed vines. Diggings made in search of larvae showed a similar 
condition. Only three larvae were found about the roots of five 
sprayed vines as against 55 larva? found about the roots of five un- 
treated vines. The crop value for the season of 1909 for the 5 acres 
was $213.92 as against $31.02 for the season of 1908. The vineyard 
has made sufficient growth of vines during the season to enable the 
owner to put up enough bearing canes to produce a full crop for 1910. 

The additional cost of the operations of spraying and fertilizing for 
the seasons of 1908 and 1909, over and above ordinary vineyard 
management, amounted to $135, itemized as follows: 

Nitrate of soda, 1,000 pounds $25. 00 

Complete fertilizer, 2 tons 70. 00 

Spray material and labor, $4 per acre 40. 00 

The success of this attempt to restore this 5 acres of vineyard to 
its former state of productivity can not be better summarized than 
by presenting the following figures showing net weight of fruit and 
the crop value for the years 1904 to 1909, inclusive: 

Pounds. Value. 

1904 11,630 $127.51 

1905 23,705 410.77 

1906 21, 130 435. 72 

1907 3,195 55.92 

1908 4,390 31.02 

1909 19,935 213.92 



REMEDIAL MEASURES. 83 

The owner of this vineyard is greatly pleased with the results 
obtained by the treatment described above and is satisfied that a con- 
tinuation of these methods will in another season restore his vine- 
yard to its full bearing capacity of 1905. It might be added that 
previous to this experiment Mr. Mosher was very skeptical regarding 
the possibility that this pest could work such havoc in vineyards 
and also as to the value or necessity of a spray treatment. During 
this experiment, however, he has become a thorough convert, and 
is satisfied that the intelligent use of a poison spray has been the 
chief factor in the restoration of his vines. 

SPRAYS. 
ARSENICAL POISONS. 

Arsenic in some form or other is usually the active killing agent 
used against insects which secure their food by chewing upon the 
foliage or fruit of plants, and since the grape root-worm beetles belong 
to the category of chewing insects the direct killing agent (or stomach 
poison) applied to grapevines is the arsenical poison which the spray 
mixture contains. 

There are several forms of arsenicals used as insecticides. Those 
that have been most commonly used in the past are Paris green and 
arsenite of lime. Arsenite of lime is a common home-prepared 
insecticide made by boiling together, for about 20 minutes, 1 pound 
of white arsenic with 4 pounds of sal-soda crystals in 1 gallon of 
water. This is known as the Kedzie formula; and when used with 
water, milk of lime made by slaking 2 or 3 pounds of good stone lime 
must always be added to 50 gallons of the mixture; for the boiling 
of the sal-soda with the arsenic is simply to put all of the arsenic 
into solution in order that all of it may unite with the lime to form 
arsenite of lime. When used with Bordeaux mixture this addition of 
lime is not necessary. 

Another arsenical poison and the one which has largely displaced 
both Paris green and arsenite of lime as a stomach poison for use on 
foliage is arsenate of lead. In properly made arsenate of lead less 
than 1 per cent soluble arsenic is present, whereas in Paris green and 
arsenite of lime a much higher percentage of arsenic may be soluble 
or exist in a weakly combined state, and since it is this soluble arsenic 
which is injurious to foliage a much higher strength of the arsenate 
of lead can be used without danger of injuring the foliage. In 
addition to having this advantage the lead base makes the arsenate 
of lead much more adhesive to the foliage than either Paris green 
or arsenite of lime. The chief element in favor of the two latter 
arsenicals is that they are somewhat cheaper than arsenate of lead. 
However, within the past few years the increased consumption of 



84 THE GEAPE EOOT-WOEM. 

arsenate of lead for spraying purposes and the sharper competition 
among manufacturers to secure the trade have been the means of 
considerably lowering its cost to the consumer and the matter of 
price should no longer be a bar to its use. 

COMBINING INSECTICIDES WITH FUNGICIDES. 

Since the use of a fungicidal spray for grapevines is highly desirable 
and frequently absolutely necessary to hold in check fungous dis- 
eases such as mildew and black-rot, and since some of the applica- 
tions for these fungous diseases and the insect pest may be made 
at the same date, it has become customary to combine the two 
treatments by adding poison in the form of arsenate of lead to Bor- 
deaux mixture, the fungicide used against the fungous diseases. 

The formula recommended for this combined treatment is asfollows: 

Pounds. 

Copper sulphate (blue vitriol) 5 

Fresh stone lime 5 

Arsenate of lead 3 

Water 50 

When Paris green or arsenite of lime are the arsenicals used, 4 
ounces of the former, or 1 quart of the latter prepared according to 
Kedzie's formula, may be added to 50 gallons of Bordeaux mixture. 
For reasons given above the use of arsenate of lead in preference to 
either of these other arsenicals is strongly urged. We here include 
detailed directions for making Bordeaux mixture which are given 
by Mr. C. L. Shear, of the Bureau of Plant Industry, in Farmers' 
Bulletin 284, treating of fungous diseases of the grape. 

PREPARATION OF BORDEAUX MIXTURE. 

Failure to secure satisfactory results from the use of Bordeaux 
mixture is frequently due to lack of proper care and thoroughness in 
its preparation, or to the use of poor material. All ready-made 
preparations of Bordeaux mixture in the form of a paste or a dust 
should be avoided, as the chemical constitutents do not properly 
combine in these conditions. A definite chemical compound is desired, 
and this can only be produced in proper form and condition by care- 
fully following the directions given below: 

Stock solution. — In order to carry on the work with the greatest convenience and 
economy, a considerable quantity of copper sulphate and of lime should be ready for 
immediate use. The copper and the lime may be prepared and kept most conven- 
iently in the following manner: 

Copper sulphate solution. — Take 100 pounds of copper sulphate (bluestone), place 
it in a gunny sack, and suspend it in a 50-gallon barrel of water. Kerosene or whisky 
barrels will be found very convenient. The copper sulphate will all dissolve in from 
12 to 18 hours if suspended in a loosely-woven sack, but if it is thrown loose in the bot- 
tom of the barrel it will take several days and considerable stirring to dissolve it. This 



REMEDIAL MEASURES. 85 

makes a solution containing 2 pounds of copper sulphate to each gallon of water. This 
may be kept as long as desired without deterioration, if covered so as to prevent 
evaporation . 

Lime solution. — The various kinds of ground and prepared lime can not always be 
relied upon; stone lime is therefore to be preferred, and is more likely to give uni- 
formly satisfactory results. Slake 100 pounds of stone lime in a 50-gallon barrel, add- 
ing the lime in small quantities with sufficient water and mixing thoroughly. When 
the lime is all slaked fill the remainder of the barrel with water. You will now have a 
stock preparation of lime which when thoroughly mixed will be thin enough to dip, 
and pour readily. Each gallon of this preparation will contain 2 pounds of stone lime. 
This may be kept under cover and used as needed. Where large quantities of mate- 
rial are being used it is desirable to have two or more barrels each of stock lime and 
bluestone instead of one, so that the bluestone in one barrel may be dissolving while 
that in the other is being used. 

Mixing copper sulphate solution and lime solution. — To prepare a 100-gallon spray 
tank of Bordeaux mixture, take two 50-gallon barrels and fill them nearly full of water; 
to one barrel add 5 gallons of the bluestone stock solution, which will be equivalent 
to 10 pounds of bluestone. To the other barrel add 5 gallons from the barrel of the 
stock lime preparation, which will be equal to 10 pounds of stone lime. Mix the lime 
thoroughly and allow the contents of the two barrels to run together in a trough, or 
through hose attached at the bottom of the barrels into the tank of the sprayer. 

If an insecticide is to be used, it may now be added to the mixture. 

After the mixture is prepared it should be used very soon, and not be allowed in any 
case to stand more than a few hours before using. 

The quantities mentioned in this account of the preparation of Bordeaux mixture 
will give 100 gallons of the 5-5-50 formula. For the other formulas, the manner of 
preparation is precisely the same, and the necessary changes in quantities of blue- 
stone and lime are easily calculated. 

PLANTS FOR PREPARATION OF THE SPRAY MIXTURE. 

Plate X, figure 1, shows a mixing plant erected beside a creek in 
a vineyard, using a hydraulic ram to elevate the water to the tank, 
the lime being slaked and the copper sulphate dissolved in the bar- 
rels standing upon the ground. An abundant water supply which 
can be delivered to the sprayer tank either by pressure or by gravity 
greatly minimizes both the cost and labor of preparing spray mix- 
tures and in addition saves a great deal of time at a season when the 
vineyardist is almost overwhelmed with the routine work of vine- 
yard operations. 

Lack of preparation for spraying operations and failure to utilize 
to the greatest advantage the flow of water down creeks or from 
springs adjoining vineyards, either by gravity or by the use of hydrau- 
lic rams, to elevated mixing stations frequently cause the vineyard- 
ist who is rushed with work either to neglect spraying entirely or 
to be so delayed in making the application that it is only partly 
effective; whereas if plans are made in advance to simplify the mixing 
and loading of the spray mixture, the apparent magnitude of the task 
is greatly lessened. The thing of prime importance is for the vine- 
yardist to become thoroughly convinced that spraying is one of the 
absolutely necessary operations in successful vineyard management. 



86 THE GRAPE ROOT-WORM. 

TIME OF APPLICATION OF SPRAYS. 

Much time and labor is actually wasted in making spray applica- 
tions after beetles have done considerable feeding and deposited 
many of their eggs. The necessity of having all equipment and mate- 
rial in readiness to make the first application as soon as the first 
beetles appear can not be too strongly emphasized. There is no 
doubt that the indifferent results secured from spraying by many 
vineyardists is largely due to failure to make the first application as 
soon as the first beetles appear upon the vines. 

Unfortunately no definite date can be set for the making of this 
first application on account of the wide range in the date of emergence 
of beetles from the soil from year to year, due to variations in sea- 
sonal temperature conditions, especially during the spring months. 
Our records show that the beetles emerged fully three weeks later in 
1907 than in 1908 and spraying operations had to be planned 
accordingly. 

Normally the first beetles may be expected to appear between the 
20th and 25th of June. It should not be inferred, however, that the 
insect does not exist in the vineyards in serious numbers if the 
beetles are not in evidence at the latter date, for it happens that 
even experts have been led astray, as occurred in Chautauqua County, 
N. Y., in the spring of 1907, when experts visited the grape belt dur- 
ing the first week in July and, finding no beetles at this date, inferred 
that the pest no longer existed in very injurious numbers. Yet late 
in July it was found that beetles had emerged in enormous numbers 
in many vineyards throughout the area visited. This emphasizes 
the fact that only by the closest observation can the vineyardist 
determine the damage which this insect may inflict upon his vines 
and he must be fully prepared every season to combat the pest on its 
first appearance. A more detailed discussion of the changes in time 
of emergence of the beetles from year to year is given under the head 
of seasonal history of the insect. 

NUMBER OF SPRAY APPLICATIONS. 

During this investigation it has been learned that two thorough 
spray applications will reduce this pest to numbers which will not 
materially affect the health of the vine or the production of profitable 
crops. The second application should be made about a week or ten 
days after the first to cover the growth of new foliage which has 
developed, and also to destroy those beetles which may not have 
emerged from the soil at the time the first application was made. 
Since rearing records indicate that the maximum number of beetles 
emerge within the period of ten to fifteen days after the first beetles 
appear (see fig. 23) the small percentage of late emerging beetles will 
not be likely to effect very great injury. The fact that there is some 



Bui. 89, Bureau of Entomology, U. S. Dept. of Agriculture. 



Plate X. 




Spraying Outfits for Vineyards, in Use at North East, Pa. 

Fig. 1.— Spray-mixing plant. Fig. 2.— Gasoline-engine sprayer in operation. Fig. 3.— Compressed- 
air sprayer. Figs. 4, 5.— Horsepower or geared sprayers. (Original.) 



REMEDIAL MEASURES. 



87 



danger of staining the fruit with spray applications made much later 
than the middle of July is an additional reason for making the second 
application not later than that date. 

Nearly every season since spraying grapevines with a poison has 
become a practice there has been more or less rumor concerning ill- 
ness of persons by poisoning resulting from the eating of sprayed 
grapes. We have given considerable attention to looking up reports 
of this nature but have never been able to secure direct evidence of 
poisoning of persons in this manner. From our observations and 




Fig. oU. — Young grapevine sprayed with arsenate of lead against the beetles of the grape root-worm. 
North East, Pa., 1909. (Original.) 

experiments with poison sprays against the grape root-worm beetle 
and all other insect pests known to us at present in vineyards in the 
Lake Erie Valley, all applications should be made in normal seasons 
not later than the middle of July, and in exceptionally late seasons 
like that of 1907 not later than July 25. If vineyardists will en- 
deavor to make their last poison application before that date they 
need have no fear of either staining their fruit or creating cause 
for rumor of poisoning by persons consuming the same and also 
may feel assured that they have made the applications at a period 
when they will prove most effective in the control of this pest. 



05 THE GRAPE ROOT-WORM. 

PRESSURE TO BE MAINTAINED IN SPRAY APPLICATIONS. 

In order that effective results may he obtained with poison sprays 
it is very desirable that, as nearly as possible, all of the foliage be 
covered with a mistlike spray. (See fig. 30.) Since in many vine- 
yards having thrifty growing vines the foliage is quite dense during 
the latter part of June and early July it is necessary that this finely 
divided spray be thrown into the vines with considerable force. For 
effective work a steady pressure of not less than 100 pounds should 
be maintained and if this can be increased to 125 or 150 pounds still 
better work may be accomplished. 

SPRAYING APPARATUS. 

In order to cover vineyard areas of several acres in this manner it 
has become necessary to use power sprayers and during the past few 
years several types of power vineyard sprayers have come into use. 

Horsepower sprayers. — Geared sprayers operated by horsepower (PI. X, figs. 4, 5) 
are in general use in many vineyard sections. There are a number of sprayers of 
this type upon the market. With many of them, however, it is difficult to maintain 
a sufficiently high pressure to cover thoroughly all of the foliage without driving 
through the vineyard at too rapid a rate. In addition to this the nozzle arrangement 
is not adjusted so as to cover the foliage on the top of the trellis. A very unpleasant 
feature in the operation of many of these machines is that the driver is seated directly 
between the nozzles which are attached to the sides of the machine and consequently 
is drenched with the spray. It would seem however, that with a little ingenuity on 
the part of the manufacturers this unpleasant seating position and ineffective nozzle 
arrangement could be satisfactorily adjusted. 

Gasoline-engine sprayers. — Many vineyardists prefer to have the power for pro- 
viding pressure independent of the rate at which the machine travels through the 
vineyard and more directly under the control of the operator than it is with the geared 
sprayers. Since, however, the regulation gasoline-engine outfit used for spraying 
orchards is too heavy and cumbersome to use in the narrow rows of vineyards it has 
become necessary to mount the tank and machinery on a specially constructed shortened 
truck having low front wheels to admit of easy turning into the narrow vineyard rows. 
Plate X, figure 2, is an illustration of this type of gasoline-engine vineyard outfit and 
is the sprayer used for the past three seasons in making the application of poison 
sprays in the field experiments conducted during this investigation. An outfit of 
this kind has the additional advantage of being adaptable for use as an orchard outfit 
by simply disconnecting the fixed nozzles at the pump and connecting a lead of hose 
and rod when wishing to spray trees. It was for the purpose of tree spraying that the 
derrick or platform was erected above the tank. When used for vineyard work the 
derrick proved useful as an elevated seat where the driver would be clear of the spray. 
(See PI. X, fig. 2.) 

Compressed-air outfits. — Compressed-air outfits are a type of sprayer which find 
favor with a number of vineyardists and perform excellent work. The air is com- 
pressed by means of a stationary engine at the loading station and one of the cylin- 
drical tanks is charged with air and the other filled with the spray liquid. The two 
tanks are connected so that the air may pass into the tank containing the liquid and 
force it out through the nozzles in the form of a fine spray. Since there is no machin- 
ery connected with this sprayer except at the loading station there is practically 
no danger of delay from machinery getting out of order while working in the field. 



RECOMMENDATIONS. 89 

Carbonic-acid-gas sprayers. — Carbonic acid is employed as power in a similar manner 
to compressed air. It is, however, somewhat more expensive than either horsepower 
engines, gasoline engines, or compressed air. More or less difficulty sometimes occurs 
in procuring the drums of gas, which have to be obtained from large cities where this 
gas is manufactured. Yet there are many of these outfits in use and giving good 
satisfaction. 

Hand pumps. — Where but limited areas of vineyard are to be treated quite effect- 
ive work may be done with a pump operated by hand to treat vines, and in gardens 
or places where it is impossible to drive a cart a knapsack sprayer may be used. For 
larger areas, however, it will be found more economical to use power outfits. 

The care of spraying apparatus. — For the successful operation of spray pumps it is 
highly desirable that the working parts be made of brass, since iron is acted upon 
by Bordeaux mixture. It is also important that the pump be so constructed that 
packing can be conveniently removed and replaced. Each time after the pump is 
used a few pailfuls of water should be run through the pump, hose, and nozzles to 
remove all of the spray mixture so that sediment in the mixture may not dry up and 
clog the valves and nozzles while the machine is not in use. If this precaution is 
taken much annoyance may be avoided when the machine is next put in operation. 

Nozzle adjustment. — Practically all of the power sprayers are equipped with adjust- 
able nozzles attached to a vertical rod firmly fastened to the sides of the tank, usually 
at the rear end of the machine. There are usually two or three of these nozzles set 
horizontally to throw the spray into the side of the vines. In addition to these hori- 
zontally directed nozzles, the uppermost nozzle 
should be carried out over the top of the trellis and 
directed downward to insure the covering of all the 
foliage on the top of the trellis (PI. X, figs. 2, 3), 
since it is upon the new growth developing at the top 
of the trellis that the beetles are likely to do much 
feeding, especially after the lower foliage has been 
thoroughly covered with a spray mixture. 

Nozzles. — Nozzles of the Vermorel type are the 
kind in general use for vineyard spraying and pro- 
duce a fine mistlike spray which is so necessary for FlG - 3L ~ A lar ^ e nozzle of the c ^ 

, f ',. , J clone type. (Original.) 

effective work, and tor this reason they are more 

desirable than nozzles of the Bordeaux type, which throw a heavier, fan-shaped 
spray. The chief drawback with the ordinary Vermorel nozzles lies in the rapid 
wearing out and enlarging of the opening of the cap, resulting in a coarse spray if 
allowed to become too much worn. More recently larger nozzles of the Cyclone type 
(fig. 31) have come into general use, especially where high pressure with power 
machinery is used. These nozzles throw a larger cone of spray, have steel disks for 
caps, which can be removed when the opening becomes much worn, and possess 
the added advantage of not clogging so readily as the smaller Vermorel nozzles. 

RECOMMENDATIONS. 
DESTRUCTION OF THE ADULTS OR BEETLES. 

The beetles of the grape root-worm feed upon the upper surface 
of the leaves of the grapevine, and may be poisoned by thoroughly 
spraying the foliage of the vines with an arsenical. The first poison- 
spray application should be made as soon as the first beetles are 
found upon the vines. Our observations indicate that the beetles 
feed much more freely immediately after emergence from the soil 




90 THE GEAPE ROOT-WORM. 

than they do several days later, during the period of egg deposition, 
and since the object of this application is to prevent egg deposition, 
it is very desirable that the poison application be made early, so 
that the first meal of the beetle will consist of poisoned foliage. 

The beetles may be expected to appear on the foliage during the 
last week or ten days in June or the first few days in July, depending 
on the earliness of the season. After June 20 vineyardists should 
keep a sharp watch for their appearance and have their spray equip- 
ment in readiness to make the first spray application. 

The development of the pupa in the soil will also indicate approxi- 
mately the appearance of the beetles, for they may be expected to 
appear within a week or ten days after the pupae can be found in the 
soil in considerable numbers. Since a large majority of the beetles 
emerge from the soil from ten to fifteen days after the appearance 
of the first beetles, it is necessary to make a second spray applica- 
tion within a week or ten days after the appearance of the first 
beetles. In this way it will be possible to keep the foliage well 
covered with poison spray during the emergence of a maximum 
number of the beetles. 

Observations and experiments indicate that, if these two appli- 
cations are made promptly and thoroughly, this pest can be reduced 
to such small numbers that it will not materially affect the vigor of 
the vines. 

The spray formula recommended is as follows : 

Arsenate of lead pounds. . 3 

Water gallons. . 50 

Copper sulphate (blue vitriol) pounds . . 5 

Lime (fresh lump lime) do 5 

The first ingredient of the formula, arsenate of lead, is the arsenical 
poison and the active killing agent or insecticide. The two last 
ingredients, copper sulphate and lime, with the water, form Bordeaux 
mixture, which is a fungicide used to control black rot, mildew, and 
other fungous diseases of the grape. Fortunately this insecticide 
and this fungicide can be mixed without changing the quality of 
either, and for this reason their use in combination is recommended. 

DESTRUCTION OF THE PTJP.E. 

In the vineyards throughout the Lake Erie grape belt pupation of 
the grape root-worm may be expected to commence about June 10, 
reaching the maximum about June 15 to 18. These dates can not 
be fixed, however, on account of variation in weather conditions. 
The exact time of pupation of the insect can best be determined by 
the person operating the infested vineyard by carefully removing the 
soil around the base of infested vines to a depth of from 2 to 4 inches. 



KECOMMENDATIONS. 91 

When pupa? are discovered, the soil beneath the trellis should be 
removed by the horse hoe and the soil directly around the base of 
the vine carefully and thoroughly stirred with a hand hoe. The 
efficiency of this method of destroying the pupa? may be increased 
by throwing up a ridge of earth beneath the trellis during the last 
cultivation of the preceding summer. This will tend to encourage 
the insects to form their pupal cells above the roots of the vine and 
thus admit of their destruction by cultivation without serious injury 
to the roots of the vine by the horse hoe. 

It is in these two stages — namely, the pupa and the beetle— that 
the insect appears to be most readily overcome; in fact, no effective 
measures have yet been developed for the destruction of the larva? 
or of the eggs. Experiments conducted against the larva? in the 
soil with oils, carbon bisulphid, fertilizers, salt, etc., have proved 
ineffective, and in some cases injurious to the grapevine; and since 
the eggs are deposited beneath the bark of the canes when the vines 
are in full foliage, it is practically impossible to reach them with a 
spray application. 

GENERAL TREATMENT OF INFESTED VINEYARDS. 

In addition to these recommendations dealing with direct means 
of controlling the insect in producing vineyards, a few suggestions 
are offered concerning the care and treatment of newly planted 
vines, and also of old, run-down vineyards in relation to this insect 
problem. 

Serious injury is most likely to occur to young vines planted in 
soil on which infested vines were growing during the preceding 
season, for this soil is likely to be heavily infested with grape root- 
worm larva? which will transform to beetles. These emerging 
beetles readily discover the newly planted vines and soon riddle the 
leaves of these small plants. For this reason it is very desirable, 
when the replanting of an old vineyard area is found necessary, that 
some annual crop be grown for at least one season, in order that the 
soil may be free of the insect when the new vines are planted. 

In order that newly planted vines may be maintained in a thrifty 
condition during the period between planting and the bearing of the 
first crop of fruit, the vineyardist should keep a sharp watch during 
the month of July for the appearance of the grape root-worm beetles 
upon his young vines. When the beetles are numerous, they skele- 
tonize many of the leaves, and this greatly retards the growth of the 
plant. If the infested vines are thoroughly sprayed with arsenate of 
lead at a strength of 3 pounds to 50 gallons of water, the injury by the 
beetles may be in a great measure prevented. 



92 THE GRAPE ROOT- WORM. 

There is little danger that young vines will become reinfested dur- 
ing the first season, since there is a very limited amount of cane or 
stem upon which the beetle can deposit its eggs. By the second sum- 
mer, however, the area upon which eggs may be deposited is somewhat 
increased, and we have discovered occasional egg clusters of this insect 
under the loose bark of the short stem of 1 -year-planted vines and 
have also found a few larvae at their roots late in summer, indicating 
that permanent infestation may take place early in the life of the vine- 
yard. Hence it may be necessary to spray some vineyards from the 
time of planting. 

Generally it is during the third season's growth of the vines, when 
the cane is trained to the trellis, that serious permanent infestation, 
by means of egg deposition by the beetle, takes place. The larvae 
hatching from these eggs are especially injurious to these young vines, 
which possess but a limited root system compared with that of an old- 
established producing vine. It is the opinion of the writers that the 
first year or two of fruit production of young vines exposed to infesta- 
tion is the most critical period of their existence, and especial care 
should be taken during that period to prevent infestation by the 
beetles. This can be accomplished by following the suggestions made 
on pages 89-90, giving directions for the destruction of the beetles. 

When vines in a producing vineyard have been badly injured by 
this pest, such vines may frequently be renovated by cutting them 
back to the ground, so that the limited vitality of the injured vine 
may be devoted entirely to the making of vegetative growth. A 
heavy application of fertilizer should be made, consisting either of 
barnyard manure or a commercial fertilizer containing a high per- 
centage of nitrogen. The vines should be thoroughly sprayed at the 
time the beetles make their appearance and thorough cultivation of 
the soil should be maintained throughout the season. The grapevine 
possesses remarkable recuperative power and, as the results tabulated 
in this paper, under the heading of field experiments, indicate, 
responds bounteously to careful and generous treatment. 



BIBLIOGRAPHY. 

1826. Sturm, J. — Catalog meiner Insecten-Sammlung, Kiifer, pis. 4 col., pp. 1-207. 

1837. Dejean, P. F. M. A. — Catalogue des Coleopteres, Third Edition, Paris. 

1843. Sturm, J. — Catalog der Kafersammlung von J. Sturm, p. 295. 
Fidia lurida Dej., synonym flavcscens Sturm Cat. 1826. 

1847. Melsheimer, F. E. — Description of new species of Coleoptera of the United 
States. <Proc. Acad. Nat. Sci. Phila., vol. 3, pp. 158-181. 

1863. Baly, J. S. — An attempt at a classification of the Eumolpida3.<Journ. Ent., 
vol. 9, pp. 143-163. 

Original description of the genus Fidia. 

1866. Walsh, B. D. — Answers to correspondents. An undescribed species of 

Fidia. <Pract. Ent., vol. 1, No. 10, pp. 99-100. 
This insect later proved to be F. viticida Walsh. 

1867. Walsh, B. D. — The grapevine Fidia (Fidia viticida Walsh ).<Pract. Ent., 

vol. 2, pp. 87-88, fig. 

Original description of the species. 

1867. Walsh, B. D.— Grapevine beetles. <Pract. Ent., vol. 2, p. 118. 

1868. Riley, C. V. — First Annual Report Insects of Missouri, p. 132. 

1870. Riley, C. V.— Grapevine Fidia.<Amer. Ent, and Bot., Sept., vol. 2, p. 307. 
Answer to correspondent. 

1872. Kridelbaugh, S. H.— Injurious insects. <Ann. Rep. Iowa State Hort. Soc. 

for 1871, pp. 153-167. 

1873. Crotch, G. R. — Materials for the study of the Phytophaga of the United 

States. <Proc. Acad. Nat. Sci. Phila., vol. 3, pp. 158-181. 
Original description of Fidia longipes Melsh. 

1874. Chapuis, F. — Histoire naturelle des insectes. Genera des Coleopteres, vol. 

10, p. 275. 

1877. Lefevre, E. — Descriptions de Coleopteres nouveaux ou peu connus de la 
familledes Eumolpides.<Ann. Soc. Ent. France, ser. 5, vol. 7, pp. 115-166. 

1880. Stout, O. E. — Insects injurious and beneficial. <Rep. Kans. State Hort. Soc. 
f. 1879, vol. 9, pp. 86-91. 

Mention of Fidia viticida Walsh. 

1880-1892. Jacoby, M.— Biol. Centr.-Amer., Insecta, Coleoptera, vol. 6, Pt. I, p. 166. 
1885. Lefevre, E. — Catalogus Eumolpidarum.<Mem. Soc. Roy. Sci. Liege, ser. 2, 
vol. 2, separ., pp. 1-172. 

1891. Riley, C. V., and Howard, L. O.— Insect Life, vol. 3, p. 249. 

Refers to investigation in Europe of Adoxus vitis L., and mentions Fidia, the Amer 
ican related beetle. 

1892. Horn, G. H. — The Eumolpini of Boreal America. <Tran~. Amer. Ent. Soc, 

vol. 19, pp. 195-234. 

Three species of Fidia in Boreal America. Mentions synonyms of F. viticida Walsh. 

1893. Riley, C. V.— Insect Life, vol. 5, p. 18. 

Injury by F. viticida at Vineland, Ark. 

93 



94 THE GRAPE ROOT-WORM. 

1894. Ashmead, W. H. — A new genus and species of Proctotrypidae and a new 
species of Brachystichia, bred by Prof. F. M. Webster. <Journ. Cine. Soc. 
Nat. Hist., vol. 17, pp. 170-172. 

Egg parasites of the grape root-worm. 

1894. Howard, L. O. — The grapevine root- worm. < Insect Life, vol. 7, p. 48. 
1894. Webster, F. M. — Studies of the development of Fidia viticida Walsh. <Journ. 
Cine. Soc. Nat. Hist,, vol. 17, pp. 159-109, pi. 9. 

The first account of the underground habit of the grape root-worm larvae; this con- 
stitutes the more technical features of the publication in Ohio Exp. Sta. Bui. 62, 1895. 

1894. Webster, F. M. — Questions and answers. <The Ohio Farmer, January 18, 
p. 57. 

1894. Webster, F. M. — Entomology. <The Ohio Farmer, May 3, p. 357, 5 figs. 
Answers to correspondents. 

1894. Webster, F. M— Entomology. <The Ohio Farmer, June 28, p. 509. 

1894. Webster, F. M. — Inquiries and answers. <The Ohio Farmer, September 27, 

p. 257. 

Grape root-worm injury at Lawrence, Kans. 

1895. Dille, N. W. — Entomology. <The Ohio Farmer, July 11, p. 37; continued 

June 20, p. 497. 

Popular account of the grape root-worm. 

1896. Marlatt, C. L. — The principal insect enemies of the grape. <Yearb. U. S. 

Dept. Agr., 1895, pp. 391-393, fig. 98; (abstract in Amer. Nat., 1896, p. 759). 
A general account of the grape root-worm; recommends carbon bisulphid and also 
kerosene emulsion to be applied to the roots. 

1895. Webster, F. M. — The grape root-worm. <Bul. 62, Ohio Agr. Exp. Sta., Octo- 
ber, pp. 77-95, 1 pi. (Abstract in Ent. News, 1896, pp. 82-83.) 

A more detailed account of studies first published in Journ. Cine. Soc. Nat. Hist., 
1897, vol. 17, pp. 159-109; includes Ashmead's paper on egg parasites. 

1895. Webster, F. M. — Grape root-worm.<The Ohio Farmer, August 22, p. 147. 

Answers to correspondent. 

1896. Murtfeldt, Mary E. — Grapevine pest,<Colman's Rural World, St. Louis, 

Mo., March 26, pp. 75, 97. 
1896. Stimson, J. T.— Report of the horticulturist. <Bul. 43, Ark. Agr. Exp. Sta., 
p. 114, fig. 

Injury caused by F. viticida Walsh in Arkansas. 

1896. Webster, F. M. — Insects affecting the roots of the grapes. <Ann. Rep. Ohio 

State Hort. Soc, p. 31. 

Egg parasites of the grape root-worm occurring in increased numbers. 

1897. Webster, F. M., and Mally, C. W. — Insects of the year in Ohio.<Bul. 9, n. s., 

Div. Ent., U. S. Dept. Agr., pp. 40-45. 

Experiments with tobacco and kainit applied to the soil to kill larva? of the grape 
root-worm. 

1899. Lugger, O. — Beetles injurious to fruit-producing plants. <Bul. 66, Minn. 
Agr. Exp. Sta., p. 223. 

Adoius obscurus L. common on cultivated grapes in 1898. 

1899. Webster, F. M., and Mally, C. W.— Insects of the year in Ohio.<Bul. 20, 

n. s., Div. Ent., U. S. Dept. Agr., pp. 68-73. 
Grape root-worm abundant in 1897 in Ohio. 

1900. Slingerland, M. V. — The grape root-worm, a new grape pest in New York. 

<Bul. 184, Cornell Agr. Exp. Sta., pp. 21-32, 11 figs. 

An account of the grape root-worm condition in the Chautauqua grape belt; with 
compilations from Webster's papers of 1894 and 1895. 

1900. Smith, J. B. — Catalogue of the insects of New Jersey, p. 303. 

Both the European and the native grape root-worms found throughout the State. 



BIBLIOGRAPHY. 95 

1901. Howard, L. O.— Notes from correspondence. <Bul. 30, Div. Ent., U. S. 
Dept. Agr., pp. 97-98. 

Serious injury to vineyards at Bloomington, 111. 

1901. Slingerland, M. V.— Entomology. <Proc. West. N. Y. Hort. Soc. f. 1901, 

pp. 68-73. 

Mention of grape root-worm. 

1902. Doty, S. N. — Destructive grape-worms. <Journ. of Agr., St. Louis, June 26. 

General comments on the grape root-worm. 

1902. Felt, E. P. — Seventh report of the state entomologist on injurious and other 
insects of the State of New York for 1901. <Bul. 53, N. Y. State Mus., 
pp. 699-925, 6 pis., 29 figs. 

Mention of Fidia viticida Walsh. 

1902. Felt, E. P. — Grape root- worm. <Country Gentleman, May 15; June 26. 
Value of cultural methods. 

1902. Felt, E. P. — Report of the committee on insects. <6th Ann. Rep. Eastern 

N. Y. Hort. Soc, pp. 210-218. 
1902. Felt, E. P.— Grapevine root-worm. <Bul. 59, N. Y. State Mus., pp. 49-84, 
6 pis. 

Results of studies in the Chautauqua grape belt, 1902; use of beetle catcher recom- 
mended. 

1902. Felt, E. P. — Report of the committee on insects. <6th Ann. Rep. Eastern 
N. Y. Hort. Soc, pp. 210-218. (Published by New York Fruit Growers' 
Association, 1902.) 

1902. Felt, E. P. — Grapevine root-worm. <Country Gentleman, July 10, pp. 
574-575. 

Effectiveness of cultivation in the control of the grape root-worm. 

1902. Felt, E. P. — The grape root- worm. <Coun try Gentleman, May 15, 1902, p. 
413, 2 figs. 

Comprehensive account of the grape root-worm condition. 

1902. Felt. E. P. — Insects in New York, III.<Country Gentleman, April 10, p. 

308. 
1902. Johnson, W. G. — Remedies for the grape root-worm. <Amer. Agr. (New 
York), June 7, 1902, p. 750, 2 figs. 

Summary account of the life history of the grape root-worm; refers to Slingerland's 
work. 

1902. Slingerland, M. V., and Craig, J. — The grape root-worm. <Bul. 208, 
Cornell Agr. Exp. Sta., pp. 177-200, 16 figs. 

Account of infestation in Chautauqua grape belt; successful results from poison 
spray experiments. 

1902. Webster, F. M., and Newell, W. — Insects of the year in Ohio. <Bul. 31, 

n. s., Div. Ent., U. S. Dept. Agr., pp. 84-90. 

Grape root-worm, less destructive in 1901, again taking on a new vigor. 

1903. Burgess, A. F. — Remarks on the grape root-worm. <Bul. 40, Div. Ent., 

U. S. Dept. Agr., p. 34. 

Arsenate of lead spray showing good results. 
1903. Chittenden, F. H. — The principal injurious insects in 1902. <Yearb. U. S. 
Dept. Agr., 1902, p. 729. 

1903. Felt, E. P.— Grapevine root-worm. <Bul. 72, N. Y. State Mus., pp. 55, 
pis. 13. 

Replaces Bui. 59, 1. c, and contains records of further experiments with beetle 
catcher. 

1903. Slingerland, M. V.— A big fight against grape pests. <Proc Western N. Y. 
Hort. Soc. f. 1903, pp. 75-78. 

Effectiveness of an arsenical spray. 



96 THE GRAPE ROOT-WORM. 

1903. Felt, E. P. — Insecticides and notes. <Country Gentleman, January 15, p. 47. 

1903. Felt, E. P. — Summary of root-worm situation and experiments. <Country 

Gentleman, September 24, p. 828. 

Results of experiments with beetle catcher. 

1904. Burgess, A. F. — Notes on economic insects for the year 1903. <Bul. 46, 

Div. Ent., U. S. Dept. Agr., pp. 62-65. 

Grape root-worm continues to appear in injurious numbers. 
1904. Chittenden, F. H. — The principal injurious insects of 1903. <Yearb. U. S. 
Dept. Agr., 1903, p. 564. 

1904. Felt, E. P. — Recent work upon the grapevine root-worm. <Proc. Western 
N. Y. Hort, Soc. f. 1904, pp. 48-51. 

1904. Felt, E. P. — Report of the committee on entomology. <N. Y. State Fruit 

Growers Ass'n, 1904, pp. 28-29. 
1904. Felt, E. P. — Insect pests of the year. <N. Y. State Fruit Growers Ass'n, 

1904, pp. 136-139. 
1904. Felt, E. P. — Contribution for the destruction of the grape root-worm. <Grape 

Belt, June 14, p. 7. 

1904. Felt, E. P. — In the Chautauqua grape belt. <Country Gentleman, June 9, 
pp. 544-545. 

1904. Felt, E. P.— Time to get out the beetle catchers. <Grape Belt, June 28, p. 7. 
1904. Felt, E. P.— Grape-vine root- worm. <Grape Belt, Feb 9, 23; Mar. 8, 15; 
Apr. 5, 12; May 6, 17. 

Republished from Bui. 72, N. Y. State Mus., 1903; also republished in part in James- 
town Journ., Feb. 10, 1904, p. 5. 

1904. Pettit, R. H. — Insects injurious to fruits in Michigan. <Spec. Bui. 24, 

Mich. Agr. Exp. Sta., pp. 79. 
1904. Sch.effer, C. — New genera and species of Coleoptera. <Journ. N. Y. Ent. 

Soc, vol. 12, p. 227. 

Includes a key to the species of Fidia of Boreal America. 

1904. Slingerland, M. V., and Johnson, F. — Two grape pests. <Bul. 224, Cornell 
Agr. Exp. Sta., pp. 65-73, figs. 4. 

Good results from spraying experiments. 

1904. Slingerland, M. V. — Notes and new facts about some New York grape pests. 
<Bul. 46, Div. Ent., U. S. Dept. Agr., pp. 73-78, 1 fig. 

Failure of experiments with "catchers"; spraying shows encouraging results. 

1904. Slingerland, M. V. — Our insect enemies in 1903. <Proc. Western N. Y. 
Hort. Soc. f. 1904, pp. 72-77. 

1904. Washburn, F. L — Ninth Ann. Rep. State Ent. Minn. f. 1904. St. Anthony 

Park, Minn. 

Grape root-worm listed, without specific instance of its occurrence in Minnesota. 

1905. Burgess, A. F. — Some economic insects for the year 1904 in Ohio. <Bul. 52, 

Div. Ent., U. S. Dept. Agr., p. 54. 

The root-worm is reported less injurious in Ohio in 1904. 

1905. Burgess, A. F. — Some destructive grape pests in Ohio. <Bul. 5, Ohio Dept. 
Agr., Div. Nursery and Orchard Inspection, pp. 17. 

Spraying most advisable method for its control. 

1905. Chittenden, F. H. — The principal injurious insects of 1904. <Yearb. U. S. 
Dept. Agr. for 1904, p. 603. 

1905. Felt, E. P. — Twentieth report of the state entomologist on injurious and other 
insects of the State of New York for 1904. <Bul. N. Y. State Mus., pp. 35, 
95-97. (In part reprinted in the Grape Belt, June 27, 1905, p. 7.) 
Further contributions to the grape root-worm investigations. 



BIBLIOGKAPHY. 97 

1905. Felt, E. P. — Notes for the year. <Bul. 52, n. s., Bur. Eiit., U. S. Dept. 
Agr., pp. 51-52. 

Spraying may reduce the pest 50 per cent. 

1905. Felt, E. P. — New York State Fruit Growers Ass'n, Rep. Committee on Ento- 
mology. <Proc. Fourth Ann. Meet., 1905, pp. 27-30. 

1905. Felt, E. P. — Grape root-worm. <Country Gentleman, February 2, 1905, pp. 

70, 106. 

1906. Burgess, A. F.— Some economic insects of the year in Ohio. <Bul. 60, 

Bur. Ent., U. S. Dept. Agr., pp. 71-74. 

Injury to the grape root-worm in 1905 slight. 

1906. Felt, E. P. — Twenty-first report of the state entomologist on injurious and 
other insects of the State of New York for 1905. <Bul. 104, N. Y. State 
Mus., pp. 45-186. 

Further grape root-worm experiments. 

1906. Felt, E. P.— Notes for 1905 from New York. <Bul. 60, Bur. Ent., U. S. 
Dept. Agr., pp. 89-90. 

1906. Felt, E. P. — Grape root-worm. <Grape Belt, July 24, p. 5. 
Condition of infested vineyards. 

1906. Felt, E. P. — Grape root-worm. <Grape Belt, May 29, p. 1. 
1906. Felt, E. P. — Injurious Insects of 1905. <Proc. N. Y. Fruit Growers Ass'n, 
pp. 120-124. 

1906. Slingerland, M. V. — Final demonstration of the efficiency of a poison spray 

for the control of the grape root-worm. <Bul. 235, Cornell Agr. Exp. Sta., 
pp. 91-93. 

Effectiveness of a poison spray; egg parasites. 

1907. Atwood, G. G. — Some items of information for orchardings and fruit growers. 

<Bul. 1, N. Y. Dept. Agr., Bur. Hort. Insp., pp. 20. 
1907. Felt, E. P. — Twenty-second report of the state entomologist on injurious and 
other insects of the State of New York for 1906. <Bul. 110, N. Y. State 
Mus., pp. 39-186. 

1907. Quaintance, A. L. — The grape root- worm. <Farmrrs' Bui. 284, U. S. Dept. 

Agr., pp. 6-12, fig. 

1908. Felt, E. P.— Entomological Notes for 1907. <Journ. Econ. Ent., vol. 1. pp. 

148-150. 

1908. Felt, E. P. — Twenty-third report of the state entomologist on injurious and 
other insects of the State of New York for 1907. <Bul. 124, N. Y. State 
Mus. 

1908. Johnson, F. — Grape root-worm investigations in 1907. <Bul. 68, Pt. VI, 
Bur. Ent., U. S. Dept. Agr., pp. 61-68. 

History of the root-worm condition in the Lake Erie grape belt; results of experi- 
ments of 1907. 

1908. Quayle, II. J. — A new root pest of the vine in California. <Journ. Econ. 
Ent., vol. 1, pp. 175-176. 

The European grape root-worm (Adorns otscurus L.). 

1908. Quayle, H. J. — The California grape root- worm (Adoxus obscurus L.). <Bul. 
195, Cal. Agr. Exp. Sta.. pp. 26, figs. 
51282°— Bull. 89—10 7 



INDEX. 



Page. 

Adoxus obscurus, bibliographic references _ 94, 97 

related to Fidia viticida, distribution and habits 15-16 

vitis, bicolored form of Adoius obscurus 15 

vitis, bibliographic reference 93 

Ampelopsis quinqucfolia , food plant of grape root-worm 13 

Arsenate of lead against red-headed Systena 18 

and arsenite of lime, comparative effectiveness against grape root-worm beetle 68-70 

Bordeaux mixture against grape root-worm beetle 64-68,71-75,77-78,81-82,84,90 

comparison with arsenite of lime and Paris green as insecticide 83-84 

Arsenite of lime and arsenate of lead, comparative effectiveness against grape root-worm beetle 68-70 

Bordeaux mixture against grape root-worm beetle 84 

comparison with arsenate of lead and Paris green as insecticide 83-84 

Bordeaux mixture and arsenate of lead against grape root-worm beetle 64-68,71-75,77-78,81-82,84,90 

arsenite of lime against grape root-worm beetle 84 

Paris green against grape root-worm beetle 84 

directions for preparation 84-85 

Brachysticha fidix, parasite of grape root- worm 51,56-57 

Carabid beetles and their larva?, enemies of grape root-worm 50 

Cercis canadensis, food plant of grape root-worm 13 

Chrysopa sp. , enemy of grape root-worm 51 

Colaspis brunnea , mistaken for grape root-worm beetle, description and habits 18 

Craponius inicqualis, mention as enemy of grape 18 

Cremastogostcr lineolata, enemy of grape root-worm 51 

Cultural methods for destruction of pupT! of grape root-worm 61-63 

Dipterous parasite of grape root-worm 55-56 

Elm leaf-beetle. (See Galerucella luteola.) 

Fertilizers used in renovation experiment on old vineyard injured by grape root- worm 76 

young vineyard injured by grape root- worm 82 

Fidia flavescens, bibliographic reference 93 

known species 16 

longipes, bibliographic reference 93 

injurious 1o cultivated grape, distribution 16 

lurida, bibliographic reference 93 

= Fidia viticida 11 

murina— Fidia liticida 11 

viticida (see also Grape root-worm). 

bibliographic references 93-97 

copy of original description 21 

validity of naaie 11 

Fidiobia flavipes, copy of original description 51 

parasite of grape root-worm, life history 51-55 

Fungicides, combination with insecticides 84 

Grapeberry moth. (See Polychrosis viteana.) 

Grape, cultivated varieties, food plants of grape root-worm 13-14 

curculio. (See Craponius insequalis.) 

food plant of Colaspis brunnea 18 

Craponius insequalis 18 

Haltica chalybea 1" 

Macrodactylus subspinosus 17 

Polychrosis viteana 18 

Systena frontalis 17-18 

Typhlocyba comes 18 

leaf hopper. (See Typhlocyba comes.) 

production in Lake Erie Valley , 1900 to 1909 58 

root-worm (see also Fidia viticida). 
98 



INDEX. 99 

Page. 

Grape root, worm as affecting vineyards in La'ie Erie Valley 57-59 

beetle, beetles mistaken therefor 16-19 

related thereto 15-16 

description 21 

destruction '. 83-90 

seasonal history 22-33 

bibliography 93-97 

California. (See Adoxus obscurus.) 

control measures 59-89 

cultural method for destruction of pupae Cl-t3 

description of stages 19-21 

destructiveness 14-15 

development and feeding of larva before wintering 35-C6 

distribution 12-13 

egg deposition, feeding before and after it 25-28 

mating and its bearing upon it 28 

period for season of 1909 31-C2 

process 28 

variation in number of eggs per cluster 29 

depositions, numbers by individual females 29 

description 19 

incubation period 33-C5 

eggs, number per cluster, variation 29 

female beetle 30 

emergence of beetle 22-25 

experimental and rearing methods 44-50 

feeding and development of larva before wintering 35-C6 

of I leetle before and after egg deposition 25-28 

larva in spring 37 

food plants 13-14 

history 10-12 

injury, character 14-15 

insect enemies, parasitic 51-57 

predaceous 50-51 

introduction 9_10 

larva, description 19-20 

seasonal history 35-39 

life cycle as determined by rearing 40-41 

history, seasonal variations 41-44 

studies, summary 50 

longevit y of male and female beetles 32-33 

mating and its bearing on egg deposition 28 

natural enemies 50-57 

occurrence of larvae in different soils 36 

origin 12 

parasitism, double 56-57 

poison sprays against beetle in cages, experiments 64-65 

field, effect 63-64, 70-75 

experiments 66-68 

position of pupa in cell 39 

post-larval stage 38-39 

preface 3-4 

preventive measures, evolution 59-61 

pupa, description 20-21 

destruction 61-63, 90-91 

seasonal history 33^10 

pupal cell, time and making 37-38 

period, duration 40 

pupation in field and in breeding cages, time 33-40 

process 39 

rearing and experimental methods 44-50 

recommendations for destruction of beetles 89 

pupa? 90-91 

remedial measures for control 59-89 

renovation experiment on old vineyard 75-80 

young vineyard 80-83 



100 THE GRAPE ROOT-WORM. 

Page. 

Grape root-worm, seasonal history - 22-50 

variation in life history 41-44 

sprays in control 83-88 

summary of life-history studies 50 

temperature records during breeding period of 1909, North East, Pa 43 

treatment of injured vineyards 91-92 

vineyard renovation experiments, results 75-83 

vitality of newly hatched larva 35 

wintering of larva in earthen cell 36-37 

Grapes, wild, food plants of grape root-worm 13-14 

Grapevine Colaspis. (See Colaspis brunnea.) 
Fidia. (See Fidia longipes.) 
ilea-beetle. (See Haltica chalybea.) 

Haltica chalybea, mistaken for grape root- worm beetle, description and habits 17 

Ileteropus [Pediculoides] ventricosus, enemy of grape root-worm 51 

Hippodamia convergens, enemy of grape root- worm 51 

Hoplophora [Phthiracarus] arctata, enemy of grape root- worm 51 

Insecticides and fungicides, combination 84 

Lachnosterna sp., enemy of grape root-worm 51 

Lasius brunneus var. alienus, enemy of grape root-worm 51 

Lathromeris (Brachystkha) fidise, parasite of grape root- worm 51,56-57 

Macrodactylus subspinosus, mistaken for grape root- worm beetle, description and habits 17 

Nozzle adjustment for spraying vineyards 89 

Nozzles for spraying vineyards 89 

Paris green and Bordeaux mixture against grape root- worm beetle 84 

comparison with arsenate of lead and arsenite of lime as insecticide 83-84 

Pediculoides ventricosus, enemy of grape root-worm 51 

Phthiracarus arctatus, enemy of grape root-worm 51 

Polychrosis viteana, mention as enemy of grape 18 

Redbud. (See Cercis canadensis.) 
Red-headed Systena. (See Systena frontalis.) 

Renovation experiment on old vineyard injured by grape root- worm 75-80 

young vineyard injured by grape root-worm 80-83 

Rhizoglyphus phylloierx, enemy of grape root- worm 51 

Rose-chafer. (See Macrodactylus subspinosus.) 

Spraying apparatus, care 89 

for vineyard use 88-89 

Spray formula recommended against grape root- worm beetle 90 

mixture, plants for preparation 85 

Sprays against grape root- worm beetle 83-88 

number of applications 86-87 

pressure in applications 88 

time of application 86 

Staphylinus vulpinus, probable enemy of grape root- worm 51 

Systena frontalis, mistaken for grape root- worm beetle, description and habits, remedy 17-18 

Telephorid enemy of grape root- worm 51 

Temperature records during breeding period of grape root-worm during 1909 at North East, Pa 43 

Typhlocyba comes, mention as enemy of grape 18 

Tyroglyphus [Rhizoglyphus] phylloxerse, enemy of grape root-worm 51 

Vineyard conditions in Lake Erie Valley 57-59 

experiments with poison sprays against grape root- worm beetle, results 70-75 

renovation experiments against grape root- worm, results 75-83 

Vineyards, recommended treatment of those injured by grape root-worm 91-92 

Virginia creeper. (See A mpelopsis quinque folia.) 

o 



